(Not) knowing it all along

David McKenzie is one of the guys behind the World Bank’s excellent and incredibly wonky Development Impact blog. He came to Princeton to present on a new paper with Gustavo Henrique de Andrade and Miriam Bruhn, “A Helping Hand or the Long Arm of the Law? Experimental evidence on what governments can do to formalize firms” (PDF). The subject matter — trying to get small, informal companies to register with the government — is outside my area of expertise. But I thought there were a couple methodologically interesting bits:

First, there’s an interesting ethical dimension, as one of their several interventions tested was increasing the likelihood that a firm would be visited by a government inspector (i.e., that the law would be enforced). From page 10:

In particular, if a firm owner were interviewed about their formality status, it may not be considered ethical to then use this information to potentially assign an inspector to visit them. Even if it were considered ethical (since the government has a right to ask firm owners about their formality status, and also a right to conduct inspections), we were still concerned that individuals who were interviewed in a baseline survey and then received an inspection may be unwilling to respond to a follow-up. Therefore a listing stage was done which did not involve talking to the firm owner.

In other words, all their baseline data was collected without actually talking to the firms they were studying — check out the paper for more on how they did that.

Second, they did something that could (and maybe should) be incorporated into many evaluations with relative ease. Because findings often seem obvious after we hear them, McKenzie et al. asked the government staff whose program they were evaluating to estimate what the impact would be before the results were in. Here’s that section (emphasis added):

A standard question with impact evaluations is whether they deliver new knowledge or merely formally confirm the beliefs that policymakers already have (Groh et al, 2012). In order to measure whether the results differ from what was anticipated, in January 2012 (before any results were known) we elicited the expectations of the Descomplicar [government policy] team as to what they thought the impacts of the different treatments would be. Their team expected that 4 percent of the control group would register for SIMPLES [the formalization program] between the baseline and follow-up surveys. We see from Table 7 that this is an overestimate…

They then expected the communication only group to double this rate, so that 8 percent would register, that the free cost treatment would lead to 15 percent registering, and that the inspector treatment would lead to 25 percent registering…. The zero or negative impacts of the communication and free cost treatments therefore are a surprise. The overall impact of the inspector treatment is much lower than expected, but is in line with the IV estimates, suggesting the Descomplicar team have a reasonable sense of what to expect when an inspection actually occurs, but may have overestimated the amount of new inspections that would take place. Their expectation of a lack of impact for the indirect inspector treatment was also accurate.

This establishes exactly what in the results was a surprise and what wasn’t. It might also make sense for researchers to ask both the policymakers they’re working with and some group of researchers who study the same subject to give such responses; it would certainly help make a case for the value of (some) studies.

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