We study the role of the propensity scores in estimating treatment effects for the treated with a multi-valued treatment.  Assume assignment to one of the multiple treatments is random given observed characteristics.  Valid causal comparisons for the subpopulation who has been treated a...

One of the core goals of a universal health care system is to eliminate discrimination on the basis of socioeconomic status.  We test for discrimination using patient waiting times for non-emergency treatment in public hospitals.  Waiting time should reflect patients' clinical need with...

The recent blossoming of panel econometrics in general and panel time-series methods in particular has enabled many more research questions to be investigated than before. However, this development has not assuaged serious concerns over the lack of diagnostic testing procedures in panel...

The conventional Sargan (1958)/Hansen (1982) test of overidentifying restrictions and the Tilting Parameter test of Imbens, Spady and Johnson (1998) are compared in the context of the AR(1) dynamic panel data model using Monte Carlo experiments. Interestingly, the size properties of the former...

High-profile universities often face public criticism for undermining academic merit and promoting social elitism/engineering through their admissions-process. In this paper, we develop an empirical test for whether access to selective universities is meritocratic. We assume that students who...

Global frailty is an unobserved macroeconomic variable.  In event data contexts, this unobserved variable is assumed to impact the hazard rate of event arrivals.  Attempts to identify and estimate the path of frailty are complicated when observed macroeconomic variables also impact hazard...

Partial mean processes with generated regressors arise in several important econometric problems, such as the distribution of potential outcomes with continuous treatments and the quantile structural function in a nonseparable triangular model.  This paper proposes a fully nonparametric...

High frequency financial data allows us to learn more about volatility, volatility of volatility and jumps.  One of the key techniques developed in the literature in recent years has been bipower variation and its multipower extension, which estimates time-varying volatility robustly to...

Despite the well-documented increase in the relative wages and expenditures of highly-educated individuals in the U.S. in recent decades, leisure inequality mirrors inequality of wages, i.e. we observe that highly-educated individuals have now relatively less leisure time than lower-educated...