Econometrics for Policy Analysis
Paper Session
Saturday, Jan. 6, 2024 2:30 PM - 4:30 PM (CST)
- Chair: Soonwoo Kwon, Brown University
Assessing Heterogeneity of Treatment Effects
Abstract
Treatment heterogeneity is an important issue in economics, but its assessment is hindered by the fundamental lack of identification of the joint distribution of treated and control outcomes. For example, we may want to assess the effect of insurance on the health of otherwise unhealthy individuals, but it is infeasible to insure only the unhealthy ones, so the causal effects for those are not identified. Or, we may be interested in the shares of winners and losers from a minimum wage increase, but without observing the counterfactual, the winners and losers are not identified. In this paper, we derive bounds on these quantities that complement quantile treatment effects. Applications illustrate that our bounds provide useful insights on heterogeneity even when the average treatment effects are not significant.How to Sample and When to Stop Sampling: The Generalized Wald Problem and Minimax Policies
Abstract
Acquiring information is expensive. Experimenters need to carefully choose how many units of each treatment to sample and when to stop sampling. The aim of this paper is to develop techniques for incorporating the cost of information into experimental design. In particular, we study sequential experiments where sampling is costly and a decision-maker aims to determine the best treatment for full scale implementation by (1) adaptively allocating units to two possible treatments, and (2) stopping the experiment when the expected welfare (inclusive of sampling costs) from implementing the chosen treatment is maximized. Working under the diffusion limit, we describe the optimal policies under the minimax regret criterion. Under small cost asymptotics, the same policies are also optimal under parametric and non-parametric distributions of outcomes. The minimax optimal sampling rule is just the Neyman allocation; it is independent of sampling costs and does not adapt to previous outcomes. The decision-maker stops sampling when the average difference between the treatment outcomes, multiplied by the number of observations collected until that point, exceeds a specific threshold. We also suggest methods for inference on the treatment effects using stopping times and discuss their optimality.Causal Inference from Hypothetical Evaluations
Abstract
This paper develops a method that learns the relationship between hypothetical responses and real choices in observational data, and then uses that estimated relationship to predict the effect of counterfactuals. After developing the econometric theory for the estimator, we demonstrate that it can be applied in settings where standard methods are not applicable. In both a lab and field setting we show it can recover accurate estimates of treatment effects that are close to ground truth experimental estimates.JEL Classifications
- C1 - Econometric and Statistical Methods and Methodology: General
- C5 - Econometric Modeling