per year between 2013 and 2015, despite a plateau in production after 2012<sup>3</sup> (Sabet and Brown 2018; Cameron, Mishra, and Brown 2015; Savedoff 2013). Second, the internal validity—quality—of impact evaluations also has increased. There are more prospective evaluations of well-defined interventions, more field experiments, and more carefully designed quasi-experiments (IEG 2012). Third, impact evaluations are increasingly asking explicitly comparative questions on relative effectiveness by evaluating multiple treatment arms (Muralidharan and Sundararaman 2011). Finally, as the number of impact evaluations is rising, so too is the number of systematic reviews (White and Masset 2018), which rely on the existence of a range of primary studies in order to uncover generalizable findings.

All four elements—rapid growth in the number of IEs, improvements in internal validity, an increase in IEs with multiple treatment arms allowing for comparability, and an expansion in the number of systematic reviews—create more entry points through which to integrate VFM analysis into project design and decision making.

Yet as the stock of evidence grows, observers have noted that most published evaluations do not contain cost information needed for cost-effectiveness analysis (Dhaliwal et. al. 2013; McEwan 2012) or other analyses of a project’s Value for Money. Institutional production of Value for Money analyses has waned also. For example, the use of economic rates of return (ERR) at the World Bank and other multilateral development agencies has faltered and fallen out of favor. Whereas around 70 percent of the World Bank’s investment projects contained an ERR in the 1970s, about 30 percent did so in the early 2000s (IEG, 2010).

International development scholars whose work integrates impact evaluations with Value for Money analysis have noted the underutilization of CBA, CEA and other efficiency analyses in the published impact evaluation literature (McEwan 2012; Dhaliwal et. al. 2013). However, no analysis to date has determined the percentage of published impact evaluations that incorporates efficiency analysis, and there has been little systematic investigation of the observed decline in VFM application. A 2008 review found that inconsistent use of language; lack of common measures; lack of quality data on social impacts, outcomes, outputs and program cost; lack of incentives for transparency; and the expense of cost measurement all contribute to low levels of Cost reporting in the social sector (Tuan 2008).

Veteran CBA observers note that the low application of VFM analysis in impact evaluation studies and their often-dubious quality has occurred within the context of waning interest in CBA and Cost-efficiency methods more generally. This downward trend is mirrored in the quality of economic analyses in the World Bank’s project appraisal documents. In 2007 and 2008 just over half of the included economic analyses were of “acceptable” or “good

> 3 Data are from 3ie’s Impact Evaluation Repository. The repository includes published impact evaluations of development interventions carried out in low- and middle-income countries that use experimental or quasi-experimental estimation strategies with a credible counterfactual. 3ie developed the repository using systematic search of over 31 “academic databases in health, economics, public policy and the social sciences provided by platforms such as Ovid, EbscoHost and ProQuest, and libraries and websites from select research organisations and academic institutions.” More than 84,000 potential studies published between 1981 and 2015 were identified and screened, with more than 4,200 (from over 120 countries) selected for inclusion in the repository.

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