Linear Quantile Regression and Endogeneity Correction

The main two methods of endogeneity correction for linear quantile regressions with their advantages and drawbacks are reviewed and compared. Then, we discuss opportunities of alleviating the constant effect restriction of the fitted-value approach by relaxing identification conditions

The Equity Premium Puzzle and the Riskfree Rate Puzzle

This paper studies the implications for general equilibrium asset pricing of a recently introduced class of Kreps-Porteus non-expected utility preferences, which is characterized by a constant intertemporal elasticity of substitution and a constant, but unrelated, coefficient of relative risk aversion. It is shown that the solution to the "equity premium puzzle" documented by Mehra and Prescott [19851 cannot be found, for plausibly calibrated parameter values, by simply separating risk aversion from intertemporal substitution. Rather, relaxing the parametric restriction on tastes implicit in the time-addictive expected utility specification and adopting Kreps-Porteus preferences in the direction of "more realism" is likely to add a "riskfree rate puzzle" to Mehra's and Prescott's "equity premium puzzle."

A likelihood-based analysis for relaxing the exclusion restriction in randomized experiments with imperfect compliance

This paper examines the problem of relaxing the exclusion restriction for the evaluation of causal effects in randomized experiments with imperfect compliance. Exclusion restriction is a relevant assumption for identifying causal effects by the nonparametric instrumental variables technique, in which the template of a randomized experiment with imperfect compliance represents a natural parametric extension. However, the full relaxation of the exclusion restriction yields likelihood functions characterized by the presence of mixtures of distributions. This complicates a likelihood-based analysis because it implies partially identified models and more than one maximum likelihood point. We consider the model identifiability when the outcome distributions of various compliance states are in the same parametric class. A two-step estimation procedure based on detecting the root closest to the method of moments estimate of the parameter vector is proposed and analyzed in detail under normally distributed outcomes. An economic example with real data on return to schooling concludes the paper.compliers, exclusion restriction, mixture distributions, return to schooling.