How much does a good evaluation cost?

The cost of rigorous evaluations depends on many things including the question being studied, the context, and the required level of precision. So why do people complain about the cost of studies as a general principle when they vary so much? 

And why discuss costs without considering the benefits of the information they generate? The Coalition for Evidence-Based Policy contributes some evidence about costs to this debate in " Rigorous Program Evaluations on a Budget: How Low-Cost Randomized Controlled Trials Are Possible in Many Areas of Social Policy." Their brief guide describes five well-conducted, low-cost studies which ranged from $50,000 to $300,000. The introduction of random assignment in these studies comprised only a small portion of this cost (between $0 and $20,000) and the studies all produced practical and useful evidence for public policy.

Explaining rigorous evaluations well is part of the challenge ...

 

... but this video from the International Growth Centre shows it can be done . In the video, Karthik Muralidharan (University of California, San Diego) and Nishith Prakash (University of Connecticut) explain how they measured the impact of a program in Bihar, India that gave bicycles to girls as a way to promote increases in high school enrollment. Though the study results are preliminary, the method seems robust. Muralidharan and Prakash control for other factors by contrasting the change in enrollment for girls over time to the change in enrollment for boys within Bihar. They then go one step further by contrasting that difference with the comparison between girls and boys in a neighboring state that did not have the bicycle program. Smart research design; excellent explanation of results.

Extract update from Center for Global Development.