Pedro Souza

Social interactions determine many economic behaviours, but information on social ties does not exist in most publicly available and widely used datasets. We present results on the identification of social networks from observational panel data that contains no information on social ties between agents. In the context of a canonical social interactions model, we provide sufficient conditions under which the social interactions matrix, endogenous and exogenous social effect parameters are globally identified if networks are constant over time. We also provide an extension of the method for time-varying networks. We then describe how high-dimensional estimation techniques can be used to estimate the interactions model based on the adaptive elastic net Generalized Method of Moments. We employ the method to study tax competition across U.S. states. The identified social interactions matrix implies that tax competition differs markedly from the common assumption of competition between geographically neighbouring states, providing further insights into the long-standing debate on the relative roles of factor mobility and yardstick competition in driving tax setting behaviour across states. Most broadly, our identification and application show that the analysis of social interactions can be extended to economic realms where no network data exist.

How domestic constituents respond to signals of weakness in foreign wars remains an important question in international relations. In this paper, we study the impact of battlefield casualties and media coverage on public demand for war termination. To identify the effect of troop fatalities, we leverage the otherwise exogenous timing of survey collection across 26,776 respondents from nine members of the International Security Assistance Force (ISAF) in Afghanistan. Quasi-experimental evidence demonstrates that battlefield casualties increase coverage of the Afghan conflict and public demand for withdrawal, with heterogeneous effects consistent with an original theoretical argument. Evidence from a survey experiment replicates the main results. To shed light on the media mechanism, we leverage a news pressure design and find that major sporting matches occurring around the time of battlefield casualties drive down subsequent coverage, and significantly weaken the effect of casualties on support for war termination. These results highlight the crucial role that media play in shaping public support for foreign military interventions.

Social interactions determine many economic behaviors, but information on social ties does not exist in most publicly available and widely used datasets. We present results on the identification of social networks from observational panel data that contains no information on social ties between agents. In the context of a canonical social interactions model, we provide sufficient conditions under which the social interactions matrix, endogenous and exogenous social effect parameters are all globally identified. While this result is relevant across different estimation strategies, we then describe how high-dimensional estimation techniques can be used to estimate the interactions model based on the Adaptive Elastic Net GMM method. We employ the method to study tax competition across US states. We find the identified social interactions matrix implies tax competition differs markedly from the common assumption of competition between geographically neighboring states, providing further insights for the long-standing debate on the relative roles of factor mobility and yardstick competition in driving tax setting behavior across states. Most broadly, our identification and application show the analysis of social interactions can be extended to economic realms where no network data exists.

Homelessness and precarious living conditions are on the rise across much of the Western world. This paper exploits quasi-exogenous variation in the affordability of rents due to a cut in rent subsidies for low-income households in the United Kingdom in April 2011. Using comprehensive district-level administrative data, we show that the affordability shock caused a significant increase in financial distress, evictions, property crimes, insecure temporary housing arrangements, statutory homelessness, and actual rough sleeping. The most notable rise in statutory homelessness is driven by families with children, lone parents, individuals with existing health conditions, and as a result of having been evicted. We estimate that the fiscal savings were low and shifted toward the local administration: Savings by the central government were partially offset by an increase in council spending to meet statutory obligations for homelessness.