Anti-Trafficking Review

ISSN: 2286-7511
E-ISSN: 2287-0113

The Anti-Trafficking Review promotes a human rights-based approach to anti-trafficking. It explores trafficking in its broader context including gender analyses and intersections with labour and migrant rights.

DOI: 10.14197/atr.20121786

What’s Wrong with the Global Slavery Index?1

Anne T. Gallagher2


The Global Slavery Index (GSI), which has been produced by the Walk Free Foundation in 2013, 2014 and 2016, seeks to calculate the number of victims of human trafficking (or ‘modern slavery’) in each country and to assess and rank government responses. Using the latest iteration of the Index, this article examines each of the three elements (vulnerability measurement; prevalence measurement and response measurement), making some preliminary findings about the quality of the methodology and its application under each heading. It concludes with a consideration of two broader issues: (i) the conspicuous lack of critical engagement with the Index; and (ii) what the Index reveals about the changing face of anti-trafficking/anti-slavery work—most particularly, the growing involvement of metrics-focused strategic philanthropy in defining the ‘problem’ and directing responses.

Keywords: human trafficking, slavery, modern slavery, measurement, assessment, Global Slavery Index

Please cite this article as: A T Gallagher, ‘What’s Wrong with the Global Slavery Index?’, Anti-Trafficking Review, issue 8, 2017, pp. 90—112,


Since trafficking emerged, almost two decades ago, as an issue of international concern, the quest to quantify the size of the problem—and to find some way of assessing how well States are responding—has dominated the discourse and directly influenced the shape of national, regional and international responses. This is part of a much broader trend: quantification of a practice or phenomenon identified as problematic is widely seen to be an essential pre-requisite to any kind of meaningful action.3 And across the board, contemporary governance has come to rely heavily on rankings and indicators. Particularly in complex areas such as human development,4 corruption5 and the rule of law,6 indexes and other measurement tools provide (or are treated as providing) the otherwise elusive ‘evidence base’ that helps to secure support for particular responses and to rationalise decision making.7

The Global Slavery Index (GSI), which seeks to calculate the number of victims of human trafficking (or ‘modern slavery’) in each country and to assess and rank government responses, is very much a creature of this environment. The first version of the Index was released in 20138 and a revised version issued the following year.9 The most recent Index was launched in 2016.10 Its rationale was made clear from the outset. As Bill Gates advised fellow billionaire philanthropist Andrew Forrest, in order to secure traction on the issue that Forrest had committed his reputation and an undisclosed slice of his personal fortune to eradicating, he had to find some way of quantifying the problem. In Gates’ words: ‘if you can’t measure it, it doesn’t exist’.11 Just as importantly, if you can’t measure it, you cannot reliably demonstrate the impact of any interventions.

Through rigorous measurement, Gates has been able to show, very convincingly, that the work of his Foundation is making a real difference to the global disease toll. But despite references by the GSI’s authors to ‘an unfolding epidemic’,12 it is critical to point out that measuring modern slavery and quantifying disease are worlds apart. Determining whether someone has malaria or HIV; the extent to which a particular community is affected; and even the vulnerability of a given population to contracting that disease is relatively straightforward. State, private and academic institutions exist whose sole function is to do just that. They all use the same, replicable method and criteria and they all come up with results that can generally be relied upon—or at least challenged against those same methods and criteria. (While determining vulnerability to such diseases can be more difficult, the protocols are now well established.) Extrapolation—the technique of using known data to arrive at a conclusion about what is happening beyond that data range—works well in the field of public health as a way of estimating disease prevalence because our understanding of disease, our definitions and our diagnostic tools are sound and universally accepted, having emerged from a long history of inquiry, analysis and refinement.13 Disease measurement is also helped by the fact that the test population is generally readily identifiable and able to be engaged as subjects of study. Of course, these factors can come together in very different contexts. The Index’s authors note elsewhere that in the mid-nineteenth century the United States was able to accurately measure the size of its slave population.14 But this is because everyone involved knew exactly what was being counted: slavery back then was a legal fact as well as a physical reality; records were kept and the subjects of measurement were clearly not going anywhere.

‘Modern slavery’ is something quite different, not least because it is a made-up concept to which no international legal definition is attached. As used by the GSI, the term seeks to encompass under its expansive umbrella a raft of exploitative practices and a myriad of victims: from the schoolgirls abducted by Boko Haram to the abused maids of diplomatic households in London and Washington; from orphanage tourism in Cambodia to the recruitment of child soldiers by the so-called Islamic State. Even the authors of the Index have recalibrated their conception of ‘modern slavery’ from year to year, which makes comparison between their own reports a challenging exercise.15 That recalibration may also help to explain the extra ten million slaves uncovered between the Index of 2014 and that of 2016 (perhaps more convincingly than the proffered explanation that this dramatic increase reflects improvements in the methodology).16 To take the disease analogy further, there is no epidemiology of what is referred to as modern slavery: no scientific or rational basis for studying patterns, causes and effects. We don’t yet have universally accepted diagnostic criteria or credible tools of measurement—which means that universal, reliable calculation of the size of the problem, while an important goal to strive for, is not yet possible.

These difficulties are well known to those working in the field. Early editions of the US Trafficking in Persons Report (TIP Report), discussed further below, cited global figures that were later questioned by the US Government Accountability Office, which noted that ‘the accuracy of the estimates is in doubt because of methodological weaknesses, gaps in data, and numerical discrepancies’.17 The TIP Reports no longer provide global or even country estimates of prevalence, instead restricting their hard data to numbers of victims identified and traffickers prosecuted and convicted. In recent years, the International Labour Organization (ILO) has felt pressure to affirm the scale of a problem that is central to its raison d’etre.18 The ILO has a head start: forced labour is complex but, unlike modern slavery, it is defined in international law and generally well understood. Even so, the hurdles of its measurement are immense. For example, a 2005 ILO estimate of ‘at least 12.3 million people in forced labour’ increased, seven years later (under ‘a new and improved statistical methodology’), to more than 20 million.19 But despite its recent opportunistic and legally indefensible adoption of the new language of ‘modern slavery’,20 the ILO has tried to be open about the difficulties of measuring the number of those in forced labour, the fragility of the resulting data and the highly provisional nature of any conclusions based on that information.21

The Index is untroubled by such inclinations to modesty, setting itself three Herculean tasks: (i) calculating the vulnerability of individuals within each country to enslavement; (ii) measuring the total number of slaves in every country; and (iii) assessing the overall quality of government responses to modern slavery. Seeking to work out how—and how well—this has been done is itself a daunting prospect. The methodology used by the Index is complex and, in parts, opaque and incomplete, requiring considerable persistence to unravel and analyse.22 But that task, which I can only begin here, is an important one. The purpose of the Index is not just to raise awareness about human exploitation, it is also intended to provide an evidence base for ‘[advocating and building] sound policies that will eradicate modern slavery’, as well as a raft of initiatives loosely linked to Walk Free including those of a number of funds that are expected to disburse millions of dollars to support anti-slavery efforts. Others, including governments, corporations engaging in the new ‘redemptive capitalism’ around trafficking and modern slavery,23 and the many civil society bodies operating in this space will certainly use the Index selectively to advance their own agendas and interests. For these reasons alone, the Index deserves rigorous scrutiny.

This article briefly explores each of the three elements of the Index (vulnerability measurement; prevalence measurement and response measurement), making some preliminary findings about the quality of the methodology and its application under each heading. It then turns to a number of broader issues raised by the Index. Perhaps the most important of these is the lack of critical engagement from those who have the capacity—and, as I have previously argued, the responsibility—to interrogate this work carefully, openly and honestly.24 What is behind their near-complete silence? To what extent does fear of exclusion from the deep-pocketed, high profile and increasingly glamorous ‘modern slavery’ club, that counts movie stars and presidents amongst its members, play a role? Does it even matter? Is there value to the argument, which has been repeatedly made to me, that it is unfair and counterproductive to criticise those who are genuinely seeking to do good and useful work? The second, closely related issue considered in the final section, concerns the changing face of anti-trafficking work—most particularly, the growing influence of metrics-focused strategic philanthropy over how the ‘problem’ of trafficking is defined and how responses are crafted and justified. The involvement of ‘philanthrocapitalists’ such as Andrew Forrest has undoubtedly had positive effects: injecting much-needed resources and energy into an issue that has been unconscionably marginalised by States and the international community for too long. But at what cost? Does the tale of the Global Slavery Index, recounted here, herald a new way of approaching challenges that seem beyond the capacity of traditional institutions and approaches to address effectively? Or does it rather serve as a warning against abdicating power and responsibility to a political force that is, at its core, both undemocratic and unaccountable?

The Index’s Assessment of Country-level Vulnerability to Modern Slavery

The vulnerability measure assigned to each country is important because, as explained below, it is a major element in assessing the prevalence of slavery. The measure, which is significantly different to that employed by the 2014 Index, uses several dozen variables divided into four categories to work out the risk of enslavement in a particular country: (i) civil and political protections; (ii) economic, health and other social rights; (iii) personal security; and (iv) refugees and conflict.25 A country’s final ‘vulnerability score’ is calculated by averaging the sum of the variables for each category and then averaging the four resulting scores. For example, the country with the lowest vulnerability rating, Denmark, scores highly across all categories and most variables. The country with the highest vulnerability rating, the Central African Republic, receives low scores across the board.

The categories themselves generally make sense. Individuals and communities caught up in conflict will inevitably be more vulnerable than others to exploitation. Poverty and personal insecurity (measured in the Index by proxies such as being in debt and inability to raise emergency funds) also seems to be relevant as a vulnerability factor because we know that fewer resources inevitably compromise life choices and lead to risky strategies, such as irregular and debt-financed migration. But some factors chosen to assess vulnerability are less easy to reconcile and no explanation is offered. Where is the evidence to support the assertion that ‘less cell phone subscriptions per 100 people in each country is considered to be … a vulnerability factor to slavery’ or that greater access to weapons correlates with (let alone causes) increased vulnerability to slavery? Except as proxies for poverty, what do the rate of tuberculosis, undernourishment and ‘access to an improved water source’ tell us about vulnerability? Sexual orientation and disability rights are now staples of the international human rights agenda, but we are a long way from establishing a credible link between denial of these rights and increased risk of modern slavery. To turn this analysis on its head, a government that adopts an arms-reduction programme, or that actively works to reduce its tuberculosis rate, or that increases access to cell-phones through subscription can be said to be reducing vulnerability to slavery—even though none of these measures can be seriously expected to affect the national rate of forced labour, forced marriage or any other form of exploitation.

Suspicion that the seductive science of statistics and probability has trumped experience and common sense when it comes to working out vulnerability is heightened when one considers what is missing amongst the vulnerability indicators. Corruption, for example, is a straightforward vulnerability factor for exploitation. But while corruption is a heavily weighted GSI criterion for measuring the quality of government response,26 it was removed from the list of variables with an impenetrable explanation about co-linearity, Variance Inflation Factor and tolerance factors. Indeed, there are compelling indications that the availability of data points influenced, and in some cases determined, the selection of vulnerability factors and not just in relation to the criteria cited above of cell phone usage, weapons availability, health and access to water. For example, confidence in the judiciary is cited as a vulnerability factor, rather than what is perhaps the most well-established and defensible measure of vulnerability to forms of exploitation associated with modern slavery: the capacity of the State to protect citizens from violence including violent crime.27 Presumably this is because the former is supported by a contemporary data source and the latter is not.

Other oddities in the final vulnerability assessment appear to affirm fundamental weaknesses in the GSI methodology and in its application. For example, Brunei makes it on to the list of the top ten most vulnerable countries to modern slavery, above Iraq and Pakistan. This is baffling. A relatively poor score on the category of civil and political rights is probably justified for Brunei. But the Index’s assertion that tiny, oil-rich, low-crime Brunei is the worst in the world for personal security is nonsensical. It also comes as a surprise to learn that this country, which has not experienced internal conflict in living memory and neither produces nor accepts refugees, is considered by the GSI to be in poorer shape than Lebanon, Turkey and Yemen in the ‘Conflict and Refugees’ category. Another risible assertion is that, of the 167 countries surveyed, only Iceland and Denmark rank higher than Singapore as the countries where one is safest from modern slavery. Certainly, it is true that Singaporeans (much like their citizen-counterparts in Brunei) are very well insulated from the risk of exploitation. But the same cannot be said of Singapore’s 870,000 non-residents, many of whom are denied the right to unionise—and, in some sectors, the protection of a mandated minimum wage and standardised working hours.28 Exploitation of migrant workers in Singapore, especially in the construction and domestic service industries is a widely acknowledged and well-documented reality.29

The Index’s Assessment of Country-level Prevalence

 Prevalence, in this context, refers to the number of persons within a given country who, sometime over the past five years, have been subject to modern slavery, whether at home or abroad—or, in the legally unhinged language of the GSI: persons whose ‘individual freedom has been restricted in order to exploit them’. For 25 of the 167 countries assessed by the GSI, prevalence figures are based on information secured through random sample surveys conducted by the polling company Gallup during the period 2013 to 2015. Around one thousand people were interviewed in each country. Of the total pool of 29,000 respondents, just 470 affirmed that they or someone in their immediate family were or had been in a situation of forced labour or forced marriage in the past five years.30 The modest nature of these figures must be highlighted because, as discussed below, it is these 470 individuals who provide the raw data on which the entire prevalence structure of the Index is built.

For an additional two countries, the United Kingdom and the Netherlands, slavery prevalence was determined on the basis of two studies that examined rates of human trafficking (which, as the Index’s own definition admits, is not the same as ‘modern slavery’). Both studies used ‘multiple systems estimation’ (MSE), a statistical methodology popular in human rights and conflict research that utilises overlaps between incomplete information sources to estimate what might be termed the ‘dark figure’ (in this case, the number of victims who have not come to public attention and are therefore not on any available list). MSE is considered to be an alternative when the suspected low rates of prevalence make low-number random surveys unworkable. Application of this methodology by the UK National Crime Agency in 2013 supported a conclusion that the ratio between the number of detected and undetected victims is around one in four. The GSI uses that information to assert that there are presently 11,500 victims of ‘modern slavery’ in the UK—0.02% of the population. In relation to the Netherlands, the Index relied on a study commissioned by the UN Office on Drugs and Crime.31 Using the same methodology, the study found prevalence rates to be more than five times higher, at 0.104%. These substantial differences between two countries with very similar risk profiles (and consideration of the very different ways in which States identify and record victims in the first place)32 indicate that the MSE methodology requires further interrogation before it is endorsed as the go-to backup in situations where the already-problematic standard survey approach cannot be presented as a credible option.

The remaining 139 countries—those without any survey or other data point—were then divided into 12 groups, each considered, with reference to the vulnerability data, to have a common or at least similar risk profile. Each of the 12 groups was then assigned one or more of the 27 data points, (25 country survey results, the UK MSE estimate and a six-year-old survey of sexual violence in the Democratic Republic of the Congo that replaced the Netherlands MSE data). Regrettably, the detailed methodology attached to the Index does not tell us which of the 139 countries made it into which group and how multiple data points within each group were used to calculate individual country prevalence. For example, we are only told that Group 1 comprises 13 unspecified countries, the prevalence estimates of which are based on survey data from Pakistan and Nigeria and the sexual violence study from the Democratic Republic of the Congo. Group 11 comprises 17 countries, also unspecified, whose prevalence estimate is based on the MSE data from the United Kingdom. Survey data from Hungary forms the basis of prevalence estimates for 11 countries placed in Group 12.

Additional, unspecified refinements (affecting 40 of the 139 countries for which there was no survey or other data point) sought to adjust the raw group allocations to take account of unique or particular factors such as conflict and the existence of state-imposed forced labour. For example, the prevalence estimate for Uzbekistan, which would have been calculated with exclusive reference to the survey results for Russia, was recalibrated to account for the known existence of forced labourers in the agricultural sector. Other, untestable adjustments were made when the results of the extrapolation exercise failed to produce the desired results—or, in the words of the Index, when ‘selected stakeholders and country experts’ felt such adjustments were necessary to ‘better reflect known realities’. For example, while the vulnerability data on China indicated that prevalence should be measured with reference to countries such as Myanmar and India, factors such as high internet penetration, stronger infrastructure and a dramatically different level of economic growth were considered sufficiently relevant to push it to being measured with reference to Vietnam, whose country survey indicated much lower levels of vulnerability. But the reasoning behind most of the expert adjustments is much less specific. And in some cases, it doesn’t make sense. For example, Iceland, Finland, Portugal and Italy were all subject to unspecified ‘geopolitical adjustments’ on the basis of their ‘geopolitical similarities to Western Europe’.33 Unfortunately, the Index’s authors do not reflect on what the perceived need for such adjustments tells us about the validity of the underlying data.

The Index’s Assessment of Government Responses

It is impossible to explore this aspect of the Index without reference to its unacknowledged lodestar: the annual US State Department Trafficking in Persons (TIP) reports which, since 2001, have been assessing and ranking national responses to trafficking in every country, every year.34 Many States understandably object to heavy-handed scrutiny and criticism from the United States Government. But few would question their influence on legal, institutional and attitudinal change in this area. The assessment criteria used in the Reports are set out in the relevant federal statute and cover a range of factors that all fall loosely under the headings of prevention, protection and prosecution. As I have explored elsewhere, the criteria, which have been repeatedly expanded and refined through amendments to the relevant federal statute, more or less track the international legal obligations that govern State conduct in this area. The standard of the reports has improved dramatically over the years and the individual country assessments paint a necessarily incomplete but generally realistic picture of the trafficking situation and of the quality of the relevant government’s response. 35

The GSI’s assessment methodology, while clearly based on the US TIP Report approach, is much more complex. It is structured along the lines of a logical framework for a development project—complete with five overarching milestones (broad goals, sometimes confusingly referred to in the narrative as ‘outcomes’); several dozen intermediate outcomes (more specific goals, sometimes referred to in the Index as ‘activities’); almost one hundred general indicators of ‘good practice’ attached to the outcomes; and many more specific ‘description’ indicators that explain exactly what should and should not be taken into account. For example, under the milestone ‘effective criminal justice responses’, one of the three stipulated outcomes is: ‘increased number of quality prosecutions’. Attached to this outcome are seven positive indicators (e.g., training of prosecutors, establishment of special police units, etc.) and two negative ones (e.g., disproportionate punishments). The detailed descriptor indicators explain, for example, that in relation to training of prosecutors, this element requires that comprehensive training has been undertaken at least once in the past six years and that the element would not be satisfied merely with the distribution of an information booklet on relevant laws. But it’s not clear how many or what proportion of prosecutors needed to be trained or indeed, beyond proportionate sentencing, what a ‘quality’ prosecution actually looks like.

Throughout, there appears to be an in-built bias in the assessment tool towards wealthier countries. At the most basic level, the Index places a high premium on information availability, which is directly related to both capacity and resources: if information relevant to an indicator is not available, the country receives a zero score against that indicator. In other words, being unable to produce or locate information on whether long-term reintegration services have been offered to victims is treated exactly the same as not having offered any such services at all. It is only wealthy countries that could hope to meet some of the indicators such as funding or undertaking research—or developing and implementing expensive victim support programmes. And one entire milestone, ‘governments stop sourcing goods and services linked to modern slavery’, reflects an advanced response that is understandably not on the agenda of any poor or even middle-income country. A table that rates government response against GDP provides important additional perspective and balance: for example, serving to highlight Singapore’s relatively poor performance when measured against financial capacity, and the Philippines’ relatively strong one. But this one table cannot remove the in-built distortions that, like the TIP Report, will almost always see wealthy countries of destination come out on top. That is misleading on multiple levels, not least because it fails to take account of the reality that wealthy countries benefit disproportionately from the goods and services produced through cheap and exploitable labour; that the supply chains of corporations owned and run by the nationals of top-ranked countries are tainted with forced labour; and that corporate profits flowing back to these countries are vastly inflated by the cheap, exploitable labour that is often supplied by countries whose ‘anti-slavery’ responses have been judged most wanting.

Despite these critical weaknesses, the framework for assessing government response nevertheless appears to broadly reflect the current, imperfect state of our knowledge about what can be done to address ‘modern slavery’ and what might make it worse. But the Index refuses such a humble role for itself, rather projecting the framework as something much more precise and definitive. This approach is highly problematic, not least because complexities in the methodology obscure multiple assumptions and value judgments on the part of those who oversaw its creation.

These problems are brought into sharp relief when considering how country ratings are calculated. Groupings of indicators (outcomes) are evenly weighted and, with just a few exceptions, the 98 good practice indicators also receive the same weighting. What this means is that an intermediate outcome such as ‘victim-determined support is available for all identified victims’, (the holy grail of a victim-centred response that has not yet been achieved anywhere in the world), has the same value for assessment purposes as ‘domestic legislation is in line with international conventions’. It also means that both these outcomes have the same value as ‘safety nets exist for vulnerable populations’ (a wide-ranging outcome that includes indicators for markers as diverse as public sector corruption and complicity, non-discriminatory access to primary education, training of consular staff and provision of documentation to facilitate victim repatriation). Furthermore, equivalence in indicator weighting means that the indicator ‘government facilitates and funds research’ has the same absolute value as ‘government facilitates and funds labour inspections’ and that ratification of the highly contested and substantively problematic UN Migrant Workers Convention36 has the same value as ratification of the critically important UN Trafficking Protocol.

The problem is not just the false assumption of like for like across both outcomes and indicators, but also the Index transforming qualitative information into quantitative data. In order to calculate precise rankings, the Index applies a 1=yes, 0=no formula to situations, conduct or actions that can never be captured in this binary way. For example, the indicator: ‘government interventions … are evidence based’ (or, as the attached description clarifies: ‘interventions are based on strategies or theories of change identified by research’) is impossible to measure on a yes-no scale for a myriad of reasons, including the fact that research in this area is of an uneven and often very low standard and, critically, that governments themselves rarely articulate the evidence base or theory of change on which their intervention is based.

And the devil is also in the detail of how the assessment framework is actually applied. The US Government flexes its considerable political muscle to effectively coerce governments into providing certain information on their response to trafficking. This information is checked and supplemented through in-country work by the State Department that mobilises the abundant resources and contacts of US embassies throughout the world.37 The GSI assessment of government responses against each indicator uses a range of sources: desk reviews of publicly available information (including, evidently, the TIP Reports themselves); information received from governments who responded to a questionnaire (38 of the 161 countries assessed); and other information obtained through ‘in-country experts’ and online (survey-monkey) responses from and interviews with information sources identified only as ‘NGOs and partners’. 38

Certainly, it can be expected that this process yielded useful insights but there is no way to assess the quality of different information sources or indeed, to replicate the results. Thus, it is not possible to work out why the Netherlands (which was awarded the highest ranking overall in the category ‘government responses’) is so much better than the United Kingdom (which received the third-highest ranking overall). Singapore and Brunei are much closer to each other in this assessment than in relation to the other measures of vulnerability and prevalence but this convergence is not readily explicable. It is equally difficult to determine exactly how the governments of Saudi Arabia, Lao PDR and China are performing better than the governments of Singapore, South Korea and Timor Leste when it comes to responding to modern slavery. They may well be, but we have to take the Index’s word for it.

 The GSI and the Politics of Funding and Influence

Since it first appeared in 2013, media coverage of the Index has been overwhelmingly superficial and fawning.39 And the response from the broader anti-trafficking community has been oddly muted, especially when compared to the strong attacks (many of them amply justified) that have been launched against the US’s ‘name and shame’ TIP report.40 The lack of critical engagement with the Global Slavery Index from every quarter and with only very limited exceptions, is troubling and deserves scrutiny.

One powerful disincentive to criticism, devastating in its chilling effect, is the implication or accusation that attacking good works is ungenerous and unsporting. Or, as the argument has been directly put to me: ‘we are doing our best: why are you trying to undermine us?’ In public, GSI founder and funder Forrest has dismissed his critics as mere ‘academics’41 and, in his preface to the 2016 GSI Index, implies that those who point out the imperfections of the Index without offering alternatives are obstructing the ‘emancipation journey’.42 Such sentiments are not uncommon. A major Australian charity exposed for recruiting a Cambodian child to impersonate a miserable, mud-smeared sex worker for a fund-raising campaign reacted swiftly to charges of exploitation, accusing its critics of misunderstanding what was needed to ‘bring the horror home’.43 A US-based organisation that stages high profile, ethically compromised ‘rescue’ operations in impoverished countries responded with anger and bewilderment (and eventually the threat of a defamation lawsuit against the present author) when its actions were publicly challenged.44 This is all wrong. Good intentions matter but they are not enough, especially in relation to an area where the capacity to do harm—to make bad situations even worse—is demonstrably real.45

Other silencing forces, directly related to the politics of funding and influence, are also hard at work. Walk Free, the organisation that produces the GSI, and its many offshoots have come to the big table with a seductive promise of abundant funding at a time when previously generous government donors are flagging. A number of international organisations and individual experts who would be in a strong position to critically evaluate the Index have been effectively co-opted through partnerships and advisory roles.46 The example of the perennially cash-strapped ILO is particularly revealing in this regard.47 The dense web of private philanthropy woven around the modern slavery movement is evidently one that few organisations or individuals operating in this sector (with the striking exception of the Vatican)48 can afford to ignore or offend.

This situation has rendered the GSI virtually immune to criticism, even from the individuals and international organisations with the capacity to undertake a rigorous critical review of its methodology. While few have come out in open support,49 the silence from all quarters is striking. Criticising the actions of the powerful, the publicly lauded and the well-connected is never easy, especially when funding and access to influence are at stake. (The lengthy, shocking silence over the widely-known deceptions of multi-award winning anti-trafficking activist Somaly Mam50 is a sobering reminder in that regard.) But such deference is bad for the Index and for the anti-slavery movement as a whole, trapping us all in an echo chamber of like-minded and right-thinking souls who provide each other little incentive or encouragement to really interrogate how we are thinking and working.

Both the GSI and the organisation that produced it are products of ‘philanthrocapitalism’: the application of metrics and results-driven business techniques to philanthropy ‘by a new generation of self-made, hands-on donors’.51 GSI inspiration Bill Gates is the embodiment of a growing group of business leaders, entrepreneurs and former political leaders who are seeking to leverage their high public profile, along with their considerable experience, resources and contacts to engineer massive social change. Similarly prominent examples include Facebook founder Mark Zuckerberg, who is seeking to provide universal Internet access by 2020;52 the Clinton family, whose eponymous foundation is working across a broad range of issues from health to climate change;53 and George Soros, whose grant-making network the Open Society Foundations has been supporting democracy and human rights throughout the world for over two decades.54 While a belated focus of attention, the modern slavery movement is increasingly being funded—and shaped—by this new brand of philanthropy.55

The philanthrocapitalism model is a highly attractive one. Governments, with their short-term perspectives and aversion to risk, have shown themselves singularly incapable of addressing many of the most serious global afflictions—from poverty to climate change, from disease to environmental degradation. Their inaction in such areas is compounded by the failures of international institutions to foster the cooperation between countries that is required to deliver real and lasting change. The new philanthropists can bypass many of these obstacles. With ‘far-reaching time horizons and almost no one they have to please’,56 they can take on seemingly intractable social problems and assume risks that would be unacceptable to most States. The new philanthropists are also more likely than governments and governmental institutions—in theory at least—to embrace a culture of adaptive learning in which mistakes are tolerated as long as they lead to new and better ways of doing things. They have also demonstrated a much greater capacity than anyone else to build strong coalitions for change: bringing business, civil society groups, governmental bodies and intergovernmental organisations together in ways never previously possible. This can help clarify goals and can be especially useful in reducing fragmentation of effort and resources.

But the new philanthropy has also raised questions, some of them rooted in the very strengths outlined above. For example, while being answerable to nobody can certainly work to improve creativity and effectiveness, it also means a lack of transparency and accountability. Adaptation through learning may happen more quickly than might be possible within the constraints of a government aid agency, but if it does not, there is no recourse. In their business dealings, the new philanthropists remain accountable to shareholders, boards and the governments of countries within which they are headquartered and/or operating. Few if any of these constraints operate in relation to their charitable engagement. This ‘democratic deficit’, especially when coupled with expensive and efficient public relations machinery, provides effective insulation from scrutiny and criticism. To the extent that international governmental institutions allow themselves to be co-opted as partners, this deficit and its effects multiply exponentially.

And then there is the distorting effect of money and power on how a complex problem is understood and how preferred solutions are developed. As Janie Chuang has shown so well in the context of the modern slavery sector, a handful of rich, private actors have utilised their substantial resources and elite networks to directly engage in global anti-trafficking policymaking, claiming a role in global governance that has allowed them to ‘significantly influence the substantive approach to this complex problem, and even reconfigure the roles of other international actors in the field’.57 Chuang documents one prominent result of this influence: the shift in language from the painstakingly defined legal term ‘trafficking in persons’ to the legally empty but highly emotive and galvanising term ‘modern slavery’.58 Another, more recent change that can be directly traced to the influence of these new players is the growing (and it may be argued, somewhat naïve) faith in business cleaning up its ‘supply chains’ as the solution to exploitation for private profit.

Critics also point to philanthrocapitalism as treating symptoms, rather than deeper structural causes59—perhaps an inevitable side effect to an approach that values only what can be measured. The new, highly corporatised anti-slavery movement is vulnerable on this ground. As noted previously, the GSI is intended to provide the evidence base for private and public action against slavery. But that role is fatally compromised by the very assumptions upon which it is based. Put simply, the Index embodies and perpetuates a distorted—if comforting—belief that slavery is all about bad individuals doing bad things to good people. At the root of that belief is an unshakeable faith in being able to eliminate the myriad practices captured under ‘modern slavery’ without fundamentally changing how our societies and economies are organised; without a radical shift in the distribution and exercise of political and economic power. At no point does the Index or its parent organisation, Walk Free, challenge—or even gently interrogate—the underlying structures that perpetuate and reward exploitation, including a global economy that relies heavily on the exploitation of poor people’s labour to maintain growth and a global migration system that entrenches vulnerability and contributes directly to trafficking.

The GSI prevalence index implies that countries with the highest proportion of ‘slaves’ are the worst, and countries with the lowest proportion are the best. But those figures actually reveal very little about where these people are being exploited and who is benefiting from that exploitation. These weaknesses in logic are carried through to the assessment of individual country performance. Like the US TIP Report, the rankings awarded by the GSI fail, spectacularly, to tell us what is really happening. And, as shown above, they present a picture of the world that hides the benefits of cheap and exploitable labour that accrues to wealthy countries and their corporations.60 In this way, the GSI and its promoters embody what has been aptly termed ‘philanthropic colonialism’, a form of advocacy and giving that ‘just keeps the existing structure of inequality in place’.61

Ultimately, there is something deeply worrying about the commodification of structural social problems, such as human trafficking, by unaccountable private players—and the corresponding marginalisation of governments as responsible agents of change. Policy analyst David Rieff captures well the underlying paradox:

For the first time in modern history, it has become the conventional wisdom that private business—the most politically influential, the most undertaxed and least regulated, and, most importantly, the least democratically accountable sector among those groups that dispose of real power and wealth in the world—are best suited to be entrusted with the welfare and fate of the powerless and hungry. No revolution could be more radical, no expectation could be more … counterintuitive, more antihistorical, or require a greater leap of faith.62


The introduction to this article noted that the Global Slavery Index did not arise in a vacuum. The use of metrics to establish the scope of a problem, to assess progress and to legitimise responses is well entrenched across many areas. In general, the attachment to evidence that underlies this trend is to be welcomed. An accurate understanding of the scope of a particular situation—such as the number of asylum seekers and displaced in the world; the number of child soldiers; or the amount of profit generated by the illegal weapons trade—must surely help to shape more realistic policies and more effective interventions. But numbers can be manipulated to suit certain policy goals. They can be used to obfuscate as well as to clarify, to assert certainty where none exists. For trafficking, where the pressures to quantify appear to be particularly acute, the above analysis has shown that such risks are very real. It has also amply demonstrated that we do not yet have the information or the tools that are necessary to do the job properly, let alone the infinitely more complicated task of ranking the responses of every government on earth from worst to best.

The impact of a generalised failure to admit to this reality—a failure to engage honestly and openly with the problems of measurement—extends well beyond the GSI, infecting broader policy goals and processes. For example, despite widespread understanding of the difficulties attached to measuring prevalence, the new UN Sustainable Development Goals (SDG), perhaps the most important global policy initiative of this decade, will seek to assess, as a measure of progress the ‘number of victims of human trafficking per 100,000 population, by sex, age group and form of exploitation’.63 Multiple states, institutions, organisations and individuals have been quick to claim credit for getting trafficking and slavery into the SDG. However, in an apparent conspiracy of silence that echoes the lack of any serious critical interrogation of the GSI, none has publicly questioned the credibility of this critical measure of progress. To the extent that this situation is being fed by the new politics of funding and influence, it is a cause for great concern.

There are tentative but perceptible signs that we are on the verge of a transformative social revolution—a fundamental, worldwide shift in our common understanding of what one human being owes to every other. In this new moral and political universe, the idea and practice of human exploitation for private profit will be unthinkable. Andrew Forrest, Roosevelt’s ‘man in the arena’,64 deserves credit for daring greatly and striving valiantly in the cause of this revolution. But none of us working in this space is safe from the risk of mistake, overreach and hubris. It follows that no aspect of our work should be considered off-limits to scrutiny, criticism and debate.

Anne T Gallagher AO is a legal practitioner, adviser and independent scholar specialising in criminal justice, human trafficking and migrant smuggling. She is currently an adviser to the United Nations, ASEAN and the Australia-Asia Trafficking in Persons Program. Her other roles include Academic Adviser at Doughty St Chambers in London; Co-Chair of the International Bar Association’s Presidential Task Force on Trafficking; member of the IOM Migration Advisory Board; and member of the Asia Dialogue on Forced Migration Email:


1 Editor’s note: As this article draws on recently published material, it was subject to single blind peer review rather than ATR’s standard-practice double-blind review.

2 This article is a revised and extended version of: A Gallagher, ‘Unraveling the Global Slavery Index’ published in two parts in openDemocracy on 28 June 2016: and It also draws on A Gallagher, ‘Worst-offender lists biased towards rich countries won’t help us fight slavery’, The Guardian, 1 July 2016, retrieved 5 November 2016,

3 See generally the collection of essays in P Andrees and K M Greenhill (eds.), Sex, Drugs and Body Counts: The politics of numbers on global crime and conflict, Cornell University Press, New York, 2010.

4 United Nations Development Programme, Human Development Index (HDI), UNDP, 2015, retrieved 5 November 2016,

5 Transparency International, Corruption Perception Index, TI, 2016, retrieved 5 November 2016,

6 World Justice Project, World Justice Project (WJP) Rule of Law Index, WJP, 2016, retrieved 5 November 2016,

7 See generally, K E Davis, A Fisher, B Kingsbury and S E Merry (eds.), Governance by Indicators: Global power through quantification and rankings, Oxford University Press, Oxford, 2015. On the use of indicators in trafficking, see the chapter by A Gallagher and J Chuang, ‘The Use of Indicators to Measure Government Responses to Human Trafficking’, p. 326.

8 Walk Free Foundation, The Global Slavery Index (2013), WFF, 2013, retrieved 5 November 2016,

9 Hope for Children Organization Australia Ltd, The Global Slavery Index 2014, 2014, retrieved 5 November 2016,

10 Walk Free Foundation, The Global Slavery Index 2016, WFF, 2016, retrieved 5 November 2016,

11 E Behrmann, ‘Gates Helps Australia’s Richest Man in Bid to End Slavery’, Bloomberg, 15 April 2013, retrieved 5 November 2016, On the launch of the 2016 Index see A Whiting, ‘Almost 46 Million People Trapped in Slavery with North Korea, India Key Offenders: Global Index’, Thompson Reuters, 31 May 2016, retrieved 5 November 2016,

12 J Larsen, M N Datta and K Bales, ‘Modern Slavery: A global reckoning’, Significance, vol. 12, issue5, 2015, p. 33.

13 For useful insight into these aspects of disease measurement, see D Coggan, D Barker and G Rose, Epidemiology for the Uninitiated, 5th Edition, BMJ Publishing Group, London, 2003. Fourth edition available online at:

14 Larsen et al., 2015.

15 The 2013 Index states that: ‘The Walk Free definition of modern slavery includes the [international legal] definitions of [trafficking in persons, slavery and forced labour].’ (Walk Free Foundation, 2013, p. 2). The 2014 Index extends ‘modern slavery’ to include debt bondage, forced or servile marriage, and sale or exploitation of children (Hope for Children Organization Australia Ltd, 2014, p. 12). The 2016 Index states that: ‘While definitions vary, in this report, modern slavery refers to situations of exploitation that a person cannot refuse or leave because of threats, violence, coercion, abuse of power or deception, with treatment akin to a farm animal. For example, their passport might be taken away if they are in a foreign country, they may experience or be threatened with violence or their family might be threatened.’ (Walk Free Foundation, 2016, p.12).

16 Walk Free Foundation, The Global Slavery Index 2016.

17 See, for example, Government Accountability Office, Human Trafficking: Better data, strategy and reporting needed to enhance U.S. antitrafficking efforts abroad, GAO, 2006, p. 2, retrieved 5 November 2016, The latest version of the Report is open about the obstacles of going further: ‘Given the complex nature of human trafficking, it is difficult to amass reliable data to document local, regional, and global prevalence’ (US Department of State, Trafficking in Persons Report, 2016, p. 10, retrieved 5 November 2016,

18 International Labour Organization, ILO Global Estimate of Forced Labour: Results and methodology, ILO, 2012, retrieved 5 November 2016,

19 International Labour Organization, ILO Minimum Estimate of Forced Labour in the World, 2005; ILO Global Estimate of Forced Labour: Results and methodology, 2012.

20 See, for example, International Labour Organization, ILO Data Initiative on Modern Slavery, ILO, 2015, retrieved 5 November 2016, See also ILO Global Estimates of Modern Slavery, ILO 2017, retrieved 20 March 2017,

21 ILO, 2012, pp. 3-4.

22 Walk Free Foundation, Global Slavery Index 2016: Detailed Methodology, 2016, retrieved 5 November 2016,

23 E Bernstein, ‘Redemptive Capitalism and Sexual Investability’ in A Orloff, R Ray and E Savci (eds.), Perverse Politics? Feminism, anti-imperialism, multiplicity (Political Power and Social Theory, Volume 30), Emerald Group Publishing Limited, West Yorkshire, 2016, pp. 45–80.

24 A Gallagher, ‘The Global Slavery Index is based on Flawed Data: Why does no one say so?’, The Guardian, 28 November 2014, retrieved 5 November 2016, Extended version published as A Gallagher, ‘The Global Slavery Index: Seduction and obfuscation’, openDemocracy, 4 December 2014, retrieved 5 November 2016,

25 Walk Free Foundation, Global Slavery Index 2016: Detailed methodology, pp. 1–10.

26 Walk Free Foundation, The Global Slavery Index 2016, pp. 5–8.

27 G Haugen and V Boutros, The Locust Effect: Why the end of poverty requires the end of violence, Oxford University Press, Oxford, 2014.

28 M Sacco, ‘What Does Singapore Owe its Migrant Workers?’, Carnegie Council, 2016, retrieved 5 November 2016,

29 A Zwenyert, ‘Singapore’s Foreign Maids Exploited by Agents, Employers’, Thompson Reuters, 2015, retrieved 5 November 2016,

30 The final country count does not distinguish between persons involved in ‘slavery’ in the country of survey and persons involved in ‘slavery’ outside that country. This means that in relation to the Gallup survey countries, a positive response will be recorded against that country, even if the individual concerned was exploited elsewhere.

31 United Nations Office on Drugs and Crime, Multiple Systems Estimation for Estimating the Number of Victims of Human Trafficking Across the World, UNODC, 2016, retrieved 5 November 2016,

32 Even within Europe, where considerable effort has gone into standardising identification procedures, victim identification rates are not comparable because of differences in how individual States formally identify (register) victims. In the UK, for example, each potential victim who is referred to the national system for identification is noted as a potential victim for purposes of EU data collection, although it is only subsequently that a conclusive determination is made by the competent authorities as to whether or not the individual is indeed a victim of trafficking. By contrast, in other countries, such as Romania, a person is only identified as a victim of trafficking if there are criminal proceedings against a perpetrator. Accordingly, data collected across the EU on the number of victims of trafficking can only be interpreted as a sample of the problem, not the real extent of it. See A Gallagher and K Skrivankova, ‘Human Rights and Trafficking in Persons’, Background Paper prepared for the 15th Informal ASEM Seminar on Human Rights, 2015, pp. 76–77, retrieved 5 November 2016,

33 Walk Free Foundation, Global Slavery Index 2016: Detailed methodology, pp. 30–31.

34 For the full archive of reports, see:

35 A Gallagher, ‘Without Trafficking, What Would Happen to Global Wealth and Productivity?’, The Guardian, 28 July 2015, retrieved 5 November 2016,

36 Further on the Migrant Workers Convention, particularly in relation to its ambiguous place within the international legal framework around trafficking, see A Gallagher, The International Law of Human Trafficking, Cambridge University Press, New York, 2010, pp. 172–176.

37 US Department of State, Trafficking in Persons Report, 2016, p. 10.

38 Walk Free Foundation, Global Slavery Index 2016: Detailed methodology.

39 For coverage of the 2016 report, see: CNN, Global Slavery Index: 45.8 million enslaved, YouTube, 2016, retrieved 5 November 2016,; R Gladstone, ‘Modern Slavery Estimated to Trap 45 Million People Worldwide’, The New York Times, 31 May 2016, retrieved 5 November 2016,; and A Chughtai and A Abujbara, ‘Modern-Day Slavery: The numbers’, Al Jazeera, 16 August 2016, retrieved 5 November 2016, A standout exception to the deferential coverage of the Index and unquestioning acceptance of its findings is an article by the Washington Post ‘Fact checker’ on the 2014 GSI: G Kessler, ‘Why You Should be Wary of Statistics on “Modern Slavery” and “Trafficking”’, The Washington Post, 24 April 2015, retrieved 5 November 2016,

40 See, for example: J Chuang, ‘The United States as Global Sheriff: Using unilateral sanctions to combat human trafficking’, Michigan Journal of International Law, vol. 25, 2006, p. 437.

41 A Burrell, ‘Pope’s Man Walks Free from Andrew Forrest’s Anti-Slavery Push’, The Australian, 28 July 2015, retrieved 5 November 2016,

42 Walk Free Foundation, The Global Slavery Index (2016), p. 3. For a recent effort of the present author to consider alternatives, see: A Gallagher, ‘Worst-offender lists biased towards rich countries won’t help us fight slavery’, 2016.

43 L Murdoch, ‘“Poverty Porn” and “Pity Charity” the Dark Underbelly of a Cambodia Orphanage’, The Sydney Morning Herald, 5 June 2016, retrieved 5 November 2016,

44 A Gallagher and C Rover, ‘Chasing the Slave Traders: A law enforcement perspective on Operation Underground Railroad’, The Huffington Post, 31 July 2016, retrieved 5 November 2016,

45 A Gallagher, ‘Human Rights and Human Trafficking – Quagmire or firm ground?’, Virginia Journal of International Law, vol. 49, 2009, pp. 789—848, at pp. 831—832, retrieved 5 November 2016,

46 For example, the three major intergovernmental organisations involved in counter-trafficking—ILO, the International Organization for Migration and the UN Office on Drugs and Crime—have all entered into cooperative relationships with Walk Free, see: and

47 Despite its positon as the only intergovernmental organisation undertaking comparable work, the ILO has pointedly refrained from publicly analysing or even commenting on the GSI methodology and approach. In 2017 it entered into a formal partnership with Walk Free to produce an agreed, authoritative ‘Global Estimate of Modern Slavery’, see ILO Global Estimates of Modern Slavery, ILO 2017. This initiative will replace previous ILO efforts to estimate global rates of forced labour. It is not clear whether it will also replace the Global Slavery Index.

48 Four Corners, ‘Vatican Accuses Andrew “Twiggy” Forrest of Exploiting Pope Francis over Anti-Slavery Campaign’, ABC News, 5 August 2015, retrieved 5 November 2016,

49 Thus far, only those closely connected with Walk Free have publicly come to the Index’s defence. For example, Nick Grono, former CEO of the Walk Free Foundation, now CEO of the Freedom Fund, which is funded, in part, by Walk Free, champions the Index’s methodology and censures the critics who, in his words, ‘invariably fail to provide an alternative method to estimate slavery—all the while asserting the fundamental importance of measurement.’ Nick Grono, ‘Measuring Slavery Encourages Governments to do Better’, Thomson Reuters Foundation, 16 July 2016, retrieved 5 November 2016,

50 See H Hoefinger, ‘Neo-liberal Sexual Humanitarianism and Story-telling: The case of Somaly Mam’, Anti-Trafficking Review, issue 7, 2016, pp. 56—78, In 2015 a cable from the US Embassy in Phnom Penh to the State Department came to light, confirming that the local anti-trafficking community was well aware of the deceptions and malpractice within Mam’s organisation, but feared that speaking out would damage relations with donors. See D Pye and A Cuddy, ‘US was on to Somaly Mam’, The Phnom Penh Post, 1 June 2015, retrieved 20 March 2017,

51 G W Jenkins, ‘Who’s Afraid of Philanthrocapitalism?’, Case Western Law Review, vol. 61, no. 3, 2011, pp. 753—821,  p. 755. See also, ‘The Birth of Philanthrocapitalism: The leading new philanthropists see themselves as social investors’, The Economist, 23 February 2006, retrieved 5 November 2016,

52 See generally Facebook,, Facebook, 2016, retrieved 5 November 2016, Zuckerberg, the Gates Foundation and others have been credited with a leading role in formulating and adopting UN Sustainable Development Goal 9.c: ‘significantly increase access to information and communications technology and strive to provide universal and affordable access to the Internet in least developed countries by 2020’. See: Connect the World, Press, retrieved 5 November 2016,

53 See generally: Clinton Foundation, Girls and Women, The Clinton Foundation, 2016, retrieved 5 November 2016,

54 See Open Society Foundations, Home Page, Open Society Foundations, 2016, retrieved 5 November 2016, In response to the recent migrant ‘crisis’ in Europe, Soros has pledged to make half a billion dollars of investments ‘that specifically address the needs of migrants, refugees and host communities’. His explanation of how this will happen provides a useful example of philanthrocapitalism in action: ‘I will invest in startups, established companies, social-impact initiatives and businesses founded by migrants and refugees themselves. Although my main concern is to help migrants and refugees arriving in Europe, I will be looking for good investment ideas that will benefit migrants all over the world. … Our goal is to harness, for public good, the innovations that only the private sector can provide.’ G Soros, ‘Why I’m Investing $500 Million in Migrants’,, 20 September 2016, retrieved 5 November 2016,

55 For a deep and considered analysis, see: J A Chuang, ‘Giving as Governance: Philanthrocapitalism and modern-day slavery abolitionism’, UCLA Law Review, vol. 62, 2015, pp. 1516—1556.

56 J Surowieki, ‘In Defense of Philanthrocapitalism’, New Yorker, 21  December 2015, retrieved 5 November 2016,

57 Chuang, 2015, p. 1518.

58 Since Chuang’s work was published, the United Kingdom has rebranded its approach to trafficking in persons, in 2015 passing the Modern Slavery Act and creating the position Independent Anti-Slavery Commissioner.

59 Gates’ work in disease control for example, is faulted for not engaging with the dysfunctional systems that fail to protect and provide for the poor and the powerless. As one critic has noted, private initiatives to address HIV/AIDS that ignore the importance of building public health infrastructure might secure important, short-term gains, but are likely doomed to failure over the longer term. See M Edwards, Just Another Emperor? The Myths and realities of philanthrocapitalism, Demos, New York, 2008.

60 See further A Gallagher, ‘Worst Offender List biased towards rich countries won’t help us fight slavery’.

61 P Buffett, ‘The Charitable-Industrial Complex’, New York Times, 26 July 2013, retrieved 5 November 2016,

62 D Reiff, ‘Philanthrocapitalism: A (self) love story’ in The Reproach of Hunger: Food, justice and money in the twenty-first century, Verso, London, 2015, p. 229.

63 This indicator (16.2.2) is attached to Goal 8.7 (Take immediate and effective measures to eradicate forced labour, end modern slavery and human trafficking and secure the prohibition and elimination of the worst forms of child labour, including recruitment and use of child soldiers, and by 2025 end child labour in all its forms). See further: United Nations Department of Economic and Social Affairs, Sustainable Development Goals, UN, 2016, retrieved 5 November 2016,

64 Almanac of Theodore Roosevelt, The Man in the Arena, 1910, retrieved 5 November 2016,