Decomposing Triple-Differences Regression under Staggered Adoption

The triple-differences (TD) design is a popular identification strategy for causal effects in settings where researchers do not believe the parallel trends assumption of conventional difference-in-differences (DiD) is satisfied. TD designs augment the conventional 2x2 DiD with a "placebo" stratum -- observations that are nested in the same units and time periods but are known to be entirely unaffected by the treatment. However, many TD applications go beyond this simple 2x2x2 and use observations on many units in many "placebo" strata across multiple time periods. A popular estimator for this setting is the triple-differences regression (TDR) fixed-effects estimator -- an extension of the common "two-way fixed effects" estimator for DiD. This paper decomposes the TDR estimator into its component two-group/two-period/two-strata triple-differences and illustrates how interpreting this parameter causally in settings with arbitrary staggered adoption requires strong effect homogeneity assumptions as many placebo DiDs incorporate observations under treatment. The decomposition clarifies the implied identifying variation behind the triple-differences regression estimator and suggests researchers should be cautious when implementing these estimators in settings more complex than the 2x2x2 case. Alternative approaches that only incorporate "clean placebos" such as direct imputation of the counterfactual may be more appropriate. The paper concludes by demonstrating the utility of this imputation estimator in an application of the "gravity model" to the estimation of the effect of the WTO/GATT on international trade

Leases as Forms

We offer the first large scale descriptive study of residential leases, based on a dataset of ~170,000 residential leases filed in support of over ~200,000 Philadelphia eviction proceedings from 2005 through 2019. These leases are highly likely to contain unenforceable terms, and their pro-landlord tilt has increased sharply over time. Matching leases with individual tenant characteristics, we show that unlawful terms are surprisingly likely to be associated with more expensive leaseholds in richer, whiter parts of the city. This result is linked to landlords\u27 growing adoption of shared forms, originally created by non-profit landlord associations, and more recently available online for a nominal fee. Generally, such shared form leases contain worse rules for tenants than the proprietary leases they replace. Over time, it has become easier and cheaper for landlords to adopt such common forms, meaning that access to justice for landlords strips tenants of rights. We observe few within landlord effects: rather, property owners specialize in particular areas in the city. This specialization leads black tenants to be more susceptible to eviction based on crime or drug use on the premises, an effect concentrated in whiter neighborhoods. Our results offer a significant advance in the empirical study of consumer contracting, building the field by examining individual differences in adherents, geography-effects, information costs and time trends

Testing for Negative Spillovers: Is Promoting Human Rights Really Part of the “Problem”?

The international community often seeks to promote political reforms in recalcitrant states. Recently, some scholars have argued that, rather than helping, international law and advocacy create new problems because they have negative spillovers that increase rights violations. We review three mechanisms for such spillovers: backlash, trade-offs, and counteraction and concentrate on the last of these. Some researchers assert that governments sometimes “counteract” international human rights pressures by strategically substituting violations in adjacent areas that are either not targeted or are harder to monitor. However, most such research shows only that both outcomes correlate with an intervention—the targeted positively and the spillover negatively. The burden of proof, however, should be as rigorous as those for studies of first-order policy consequences. We show that these correlations by themselves are insufficient to demonstrate counteraction outside of the narrow case where the intervention is assumed to have no direct effect on the spillover, a situation akin to having a valid instrumental variable design. We revisit two prominent findings and show that the evidence for the counteraction claim is weak in both cases. The article contributes methodologically to the study of negative spillovers in general by proposing mediation and sensitivity analysis within an instrumental variables framework for assessing such arguments. It revisits important prior findings that claim negative consequences to human rights law and/or advocacy, and raises critical normative questions regarding how we empirically evaluate hypotheses about causal mechanisms

Replication Data for: Essays on Causal Inference and the International Investment Regime

The included files provide replication data for each chapter of the dissertation "Essays on Causal Inference and the International Investment Regime." The abstract is below: In the last several decades, the growth of bilateral investment treaties (BITs) and the incorporation of investment provisions into regional trade agreements has led to the development of an international legal regime defining the rules states must follow with respect to investments made by foreign nationals. Among the most controversial elements of this regime are investor-state dispute settlement (ISDS) clauses, treaty provisions which allow foreign investors to initiate arbitration directly against states for alleged breaches of the treaty. ISDS proceedings are typically held outside of any national court and the arbitrators are selected from a small cadre of elite international legal professionals. Debates over the effectiveness of investment law and the legitimacy of ISDS raise a number of important empirical questions, such as whether investment treaties are actually effective in increasing foreign direct investment, whether developing countries are systematically disadvantaged by investor-state arbitration, and whether the arbitrators deciding these disputes are truly impartial or are influenced by extralegal factors. The papers in this dissertation develop novel methodological tools in order to answer these three causal questions. The first paper evaluates the effect of bilateral investment treaties on foreign direct investment by United States firms using a differences-in-differences approach. It introduces a new differences-in-differences estimator for situations where outcomes are observed for more than two time periods. It shows how the conventional two-way fixed effects estimator yields misleading results when treatment effects persist over time and develops a new inverse propensity score weighting estimator that allows researchers to adjust for covariates without the need for restrictive assumptions on the time periods that can be affected by treatment. The second paper explores the problem of non-random attrition as applied to studies of legal disputes. It explains how analyses of dispute outcomes will be misleading when the treatment of interest also affects the propensity of a case to settle early and drop out of the data. Building on the "principal stratification'' framework, it develops a robust weighting method for adjusting for the bias due to attrition that is explained by observed covariates. It applies this approach to explain why richer countries appear to win more investor-state disputes and shows that most of the gap in observed win-rates can be explained by the fact that less wealthy countries are more likely to settle disputes early, which affects the distribution of cases that receive a final ruling. The third paper (co-authored with Sergio Puig) shows how experimental designs can supplement observational research for questions that cannot be answered from available observational data. Since investor-state arbitration mechanisms typically permit each party to appoint an arbitrator, questions have been raised about the impartiality of these party-appointed arbitrators. Unfortunately, because the vast majority of arbitral decisions are unanimous, evidence for bias is difficult to infer from case data alone. This paper presents results from a survey experiment of 257 arbitrators and arbitration experts in which respondents were asked to decide a hypothetical investor-state dispute. It finds that when arbitrators were told that they were appointed by one of the two parties to the dispute, they gave more favorable decisions to that party. These results suggest that professional arbitrators likely exhibit meaningful biases in their decision-making due to the party appointment mechanism

Replication Data for: 'Affiliation Bias in Arbitration: An Experimental Approach' and 'The David Effect and ISDS'

This repository contains replication code and data for two related papers on a set of experiments conducted on investment arbitrators: "Affiliation Bias in Arbitration: An Experimental Approach." and "The David Effect and ISDS" Consult the README file for more information about the data

Affiliation Bias in Arbitration: An Experimental Approach

A characteristic feature of arbitration, a growing form of legal adjudication, is that each disputing party appoints an arbitrator. Commentators, however, suggest that party-appointed arbitrators tend to be biased in favor of their appointers. Evaluating this claim from data on historical disputes is problematic because of nonrandom selection of arbitrators. Here we use a novel experimental approach to estimate the causal effect of the appointing party. Using survey experiments with arbitration experts around the world, we show that professional arbitrators suffer from affiliation effects—a cognitive predisposition to favor the appointing party. At a methodological level, we offer a solution to the problem of measuring this effect when credible observational designs are lacking