/* NPEST.G: procedure to estimate choice probabilities via non-parametric methods
 
            Specialized for use in estimating conditional choice probabilities to
	    implement the semiparametric two step estimator in the Prisoner's Dilemma
	    example (each choice probability, the probability of confessing or
	    not confessing) is a function of two variables (x_a,x_b) each restricted
	    to the [0,1] interval).

	    y: n x 1 vector of 0's and 1's representing the dependent variable in the
	             choice problem, viewed as a nonparametric regression where the
		     conditional choice probability, P(y|x_a,x_b), is treated as the
		     unknown regression function

            x_a,x_b  nx1 vectors containing the observed characteristics of players
	             A and B in the prisoners dilemma game.

            npemeth  a string specifying the type of nonparametric estimation method
	             to use (see setup.gpr for the options).

            John Rust, University of Maryland, October, 2006 */

    proc (1)=npest(y,x_a,x_b,npemeth);

     
       if (npemeth $== "kernel");

           retp(mvks(x_a~x_b,y,x_a~x_b));

       elseif (npemeth $== "llr");

           retp(llr(x_a~x_b,y,x_a~x_b));

       elseif (npemeth $== "series");

           retp(series(x_a~x_b,y,x_a~x_b));

       endif;

    endp;