Using Global Positioning Systems in Household Surveys for Better Economics and Better Policy

Using Global Positioning Systems in Household Surveys for Better Economics and Better Policy John Gibson David McKenzie Distance and location are the important determinants of many choices that economists study. This article reviews four ways that GPS can lead to better economics and better policy by clarifying policy externalities and spillovers, by improving the understanding of access to services, by improving the collection of household survey data, and by providing data for econometric modeling of the causal impact of policies. 6 This article reviews four ways that GPS can lead to better economics and better policy by clarifying policy externalities and spillovers, by improving the understanding of access to services, by improving the collection of household survey data, and by providing data for econometric modeling of the causal impact of policies. They also find evidence of positive spatial correlation in unobserved shocks to the productivity of fertilizer, highlighting the importance of controlling for geographic effects when examining learning. They find that naive estimates that fail to take externalities into account would underestimate the program treatment effects, leading to the mistaken conclusion that deworming is not cost-effective. Using GPS Can Improve the Collection of Household Survey Data GPS is also being used to improve the quality and cost-effectiveness of household survey data. More accurate and cost-effective surveying enables researchers to carry out better analysis and provide better evidence-based advice to policy-makers. GPS Can Be Used to Provide Data for Econometric Modeling of the Causal Impacts of Policies Most empirical work in development economics aims to identify the effect of a particular variable of interest, X, on a particular outcome, Y. A standard concern is that there are other variables that are correlated with X and that also affect Y. John Gibson and David McKenzie 225 Failure to control for these variables gives biased results. Uncertainty about how to proceed may mean that spatially explicit data are underutilized, undermining the role of data sharing and data preservation in advancing science or that researchers inadvertently disclose information that can identify survey respondents. Human-subject panels (which review the benefits and risks to subjects of research projects) can play an important role in protecting confidentiality, but researchers need to be aware of the costs of the different approaches.