I develop a new approach for sample selection problems that allows parametric forms of any type to be chosen for both for the selection and the observed variables. The Generalized Parametric Selection (GPS) model can incorporate both duration and count data models, unlike previous parametric...

This paper analyses the role of firms' R&D-experience in their innovative success using a representative sample of Spanish firms for the period 1990-2002. Using count data models and within an innovation production function approach, we investigate the influence of firms' R&D-experience in the...

This study represents the results of a comparative econometric analysis of the determinants of earnings and unemployment durations. The analysis uses two sets of panel data, one drawn from the outflows of unemployment and another from the working age population. The earnings of people leaving...

Selectivity bias caused by protest responses in Contingent Valuation studies can be detected and corrected by means of sample selection models. This paper compares two methods: the Heckman 2-steps method and the full ML, applied to data on forest recreation - where WTP is elicited as a...

This paper addresses the estimation of a semiparametric sample selection index model where both the selection rule and the outcome variable are binary. Since the marginal effects are often of primary interest and are difficult to recover in a semiparametric setting, we develop estimators for...

The literature estimating returns to education has often utilized spousal education and parental education as instrument variables (IV). However, due to usual survey designs, both IVs are available only for the individuals whose spouse or parents are present in the same household. The IV...