Working Papers

Water, Spillovers, and Free Riding: Provision of Local Public Goods in a Spatial Network (pdfSSRN) [submitted]
Decentralised provision of local public goods can lead to externalities and inefficiencies. I develop and estimate a spatial network model of communities’ water pump maintenance decisions in rural Tanzania. The model allows me to quantify the importance of cross-community free riding effects and pump maintenance spillovers. I find evidence of both effects and estimate that: (i) water collection fees mitigate free riding; (ii) pump technology standardization across communities reduces maintenance costs; (iii) increased pump functionality improves child survival and school attendance; and (iv) school attendance improves more for girls, who are primarily responsible for water collection.

Identifying Causal Effects in Experiments with Social Interactions and Non-compliance, with Francis DiTraglia, Camilo Garcia-Jimeno and Alejandro Sanchez-Becerra (pdf, arXiv[submitted]
This paper shows how to use a randomized saturation experimental design to identify and estimate causal effects in the presence of spillovers–one person’s treatment may affect another’s outcome–and one-sided non-compliance–subjects can only be offered treatment, not compelled to take it up. Two distinct causal effects are of interest in this setting: direct effects quantify how a person’s own treatment changes her outcome, while indirect effects quantify how her peers’ treatments change her outcome. We consider the case in which spillovers occur only within known groups, and takeup decisions do not depend on peers’ offers. In this setting we point identify local average treatment effects, both direct and indirect, in a flexible random coefficients model that allows for both heterogenous treatment effects and endogeneous selection into treatment. We go on to propose a feasible estimator that is consistent and asymptotically normal as the number and size of groups increases. We apply our estimator to data from a large-scale job placement services experiment, and find negative indirect treatment effects on the likelihood of employment for those willing to take up the program. These negative spillovers are offset by positive direct treatment effects from own take-up.

Work in Progress

Market-Mediated Effects of Cash Transfer Programmes, with Natalie Quinn

Distributional Effects of Cash Transfers, with Stefan Dercon, Robert Garlick, Kate Orkin and Natalie Quinn

The Spillover Effects of Financial Interventions: Evidence from a Savings Program in Ugandawith Chris Heitzig