Evidence assessment of the impacts of the criminalisation of the purchase of sex: a review

Review of evidence on the impact of the criminalisation of the purchase of sex.



In 2015, the Scottish Centre for Crime and Justice Research ( SCCJR) was tasked with work that had been identified by the Cabinet Secretary for Justice following the introduction of the Human Trafficking and Exploitation Act 2015; in recognition that this legislation had raised questions about responses to prostitution in Scotland that were not addressed within the contours of that debate.

The Cabinet Secretary gave a commitment to the Justice Committee and Parliament that research would be commissioned to "investigate the reliability of the evidence available on the criminalisation of the purchase of sex". The SCCJR was asked to do two things:

  • Produce a desk-based review of published research and evidence on prostitution [1] in Scotland;
  • Conduct a rapid assessment of existing evidence on the impact of the criminalisation of the purchase of sex.

Working alongside colleagues in Justice Analytical Services ( JAS) we set out to produce two papers which reviewed evidence in these areas.

The Process

To ensure that our work was as comprehensive as possible, a Research Advisory Group was set up by the Scottish Government consisting of six academics based in Scotland and England, who have published and researched on the topic of prostitution/sex work from different perspectives, and who are acknowledged as 'experts' on the subject area [2] . They were invited to comment on papers and reports produced, to help us to access key evidence, and to ensure that our analysis of this evidence was as rigorous as it could be.

Several points should be noted:

i. Our focus was specifically on the reliability of evidence surrounding the impact of the criminalisation of the purchase of sex. The remit meant that other legislative approaches and models were not included in the review; the absence of a comparative dimension is an obvious limitation. We are aware that without comparison with other models, this report could potentially present issues pertinent to prostitution more generally, as distinct to the criminalisation of the purchase of sex; this also means that assessing any impact of the criminalisation of the purchase of sex cannot be compared to the impacts associated with other models.

ii. Relatedly, we are aware that setting out the Scottish legal and policy context in this report could be critiqued as presenting a lens through which the evidence discussed here is viewed. However, the aim in doing so is to set out the key areas which were prioritised as a background for the assessment of impact (i.e. numbers involved in prostitution, demand, prevention and minimisation of 'harm'). While the review is framed within this policy context, its focus was to assess the reliability of evidence on the impacts of criminalisation rather than to assume that legislation is the sole, or indeed most effective, option for achieving Scottish policy objectives. Indeed, the importance of a 'package' of measures rather than any single intervention forms part of the Scottish policy framework.

Additionally, we recognise that the wider social, political and economic context is significant. For example, increased numbers involved in prostitution reflected in Sweden and Norway in 2008 has been associated with the onset of the global financial crisis rather than reflective of legislative models (Rasmussen et al, 2014). Without considering this wider context, a simple evaluation of evidence available misses structural circumstances and the resulting discourses which emerge.

Limitations of available data

As discussed throughout this review, assessing what constitutes 'evidence' on the subject of prostitution and the impact of any intervention in this area is a challenging task. We attempted to retain a focus on empirical evidence however, the underpinning discourses surrounding prostitution and the debates around legislative developments provided an important context for the review and merit ongoing consideration. Due to the limitations of existing evidence on the impacts of criminalisation we found that a relatively small number of studies were cited extensively throughout recent literature and used consistently to argue specific points. These limitations emerge partly from the challenging nature of prostitution research where the associated stigma and marginalisation make potential participants 'hard to reach' resulting in a partial overview of impacts.

Empirical evidence is largely focused on street-based prostitution and there is a universally acknowledged uncertainty about the numbers involved in indoor prostitution such as online and indoor sex work and the impacts of the criminalisation of purchase on these segments of prostitution. Attempting to distinguish 'indoor' and 'street' prostitution as separate entities is itself problematic, with individuals moving between different forms of prostitution at different points in time. We were also aware that evaluations of particular regimes require some reflection upon the aims and objectives that legislators hoped to achieve. Relatedly, the principles and values which underpin particular interventions may be distorted in practice during the implementation process; the enforcement of legislation is itself part of a political decision-making process determined by broader priorities and contemporary concerns. Unintended impacts can be caused by uneven implementation and resourcing, and different degrees of commitment to criminal justice enforcement.

This review does not set out 'conclusions' but instead, assesses the challenges that arise in attempting to draw conclusions on the basis of the existing evidence available and the limitations thereof. The reliability of existing evidence in relation to key themes has been considered [3] .


This review has highlighted the limited and contested nature of existing evidence on the impacts of the criminalisation of the purchase of sex. There is significant disagreement around some key issues which remain inconclusive within this review. The absence of comparison across different models of regulation and the assessment of evidence from other systems leaves many questions around impacts remaining. Safety, for example, was a particularly challenging issue where the existing evidence embodies various contradictions. Similarly, existing evidence is inconclusive in terms of the relationship between human trafficking and demand for prostitution; and the more general relationship between street and in-door prostitution where there exist problems of distinguishing clear divisions between different sectors and where it is impossible to provide accurate numbers. There are many areas of contention however, one point which appears to have considerable consensus is the need to decriminalise individuals involved in prostitution as 'sellers' (also a finding from the recent House of Commons Home Affairs Committee Report, 2016).

This review highlights the limitations of 'evidence' and reinforces the point made by many others that evidence on interventions in this area does not, on its own, provide an independent source for the determination of policy and/or legislation. Ultimately, the absence of conclusive evidence is likely to require decision-making based on political standpoint and consideration of the policy context and framework in which any potential intervention is required.


Email: Justice Analytical Services

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