Many proposals have emerged as alternatives to the Heckman selection model, mainly address non-robustness of its normal assumption. The 2001 Medical Expenditure Panel Survey data is often used illustrate this model. In paper, we propose a generalization sample model by allowing bias and dispersion parameters depend on covariates. We show that may be due assumption constant parameter rather than...

Karshon constructed the first counterexample to the log-concavity conjecture for the Duistermaat-Heckman measure: a Hamiltonian six manifold whose fixed points set is the disjoint union of two copies of T. In this article, for any closed symplectic four manifold N with b > 1, we show that there is a Hamiltonian circle manifold M fibred over N such that its DuistermaatHeckman function is not log...

This paper estimates wage rates using the Heckman Procedure and a tra­ ditional method. The estimation becomes necessary when the analysis requires a measure of the individual's opportunity cost of time. Since a large fraction of the adults in the sample do not participate in the labor market, the simple estimation by ordinary least squares would cause bias in the coefficients. Labor force part...

Not much equates Michael Harrington, Dwight MacDonald, Orley Ashenfelter and James Heckman. But still history made a way to have, in one end of story, narrative journalist political scientist and, the other, two economists. Harrington’s famous piece, The Other America, its into government through MacDonald’s extensive review what could have been just another edition New Yorker that January 1963...

This paper uses some basic concepts and results on harmonic analysis associated with Heckman-Opdam theory \(\mathbb {R}^{d}\) to study types of wavelet packets the corresponding transforms. More precisely, we two transforms related hypergeometric Fourier transform W-invariant functions, prove Plancherel, Calderón, reconstruction formulae for these