This paper is concerned with testing the hypothesis that a conditional median function is linear against a nonparametric alternative with unknown smoothness. We develop a test that is uniformly consistent against alternatives whose distance from the linear model converges to zero at the fastest...

We develop a new test of a parametric model of a conditional mean function against a nonparametric alternative. The test adapts to the unknown smoothness of the alternative model and is uniformly consistent against alternatives whose distance from the parametric model converges to zero at the...

Much empirical research in the social sciences is concerned with estimating conditional mean functions. The most frequently used estimation methods assume that the conditional mean function is known up to a set of constant parameters that can be estimated from data. Such methods are called...

The U.S. Drug Enforcement Administration’s (DEA’s) STRIDE data contain records of acquisitions of illegal drugs by undercover agents and informants of the DEA and Metropolitan Police of the District of Columbia. These data are widely used in economic analyses of markets for illegal drugs....