In a "fixed-effect" panel data model with a nonparametric regression function \rho(x_{it}), the usual first-differencing yields a nonparametric regression function \mu(x_{it},x_{i,t+1}) with the restriction \mu(x_{it},x_{i,t+1}) = \rho(x_{i,t+1}) - \rho(x_{it}). Although \mu(x_{it},x_{i,t+1})...

Under a sample selection or non-response problem, where a response variable y is observed only when a condition δ = 1 is met, the identified mean E(y&7Cδ = 1) is not equal to the desired mean E(y). But the monotonicity condition E(y&7Cδ = 1) ≤ E(y&7Cδ =  0) yields an informative...

This paper re-examines the GATT/WTO membership effect on bilateral trade flows, using nonparametric methods including pair-matching, permutation tests, and a Rosenbaum (2002) sensitivity analysis. Together, these methods provide an estimation framework that is robust to misspecification bias,...

We estimate a full system of structural farm and off-farm labor supply equations of farm couples as a set of simultaneous equations with categorical dependent variables. In a first step, the reduced form is estimated by ordered probit with unknown thresholds. Then, the identified structural...

There has been much recent interest in the effects of pre and non-market skills on future labor market outcomes. This paper examines one such effect : the effect on future wages of military leadership experience among "Vietnam generation" American men. We study rank, not just veteran status. We...

This paper proposes a general empirical framework to estimate the protection-for-sale model, where the protection regime shifts according to a sector's market structure (perfectly or monopolistically competitive). We base the protection structure on Grossman and Helpman (1994) for the subset of...