function [H,dH]=gmmh(theta);
%GMMHC  A user-supplied function for GMM estimation.
%       [H,dH]=gmmhc(theta) is called by GMM and GMMJC if restrict=1. 
%       H is a nobs x m (or mgmm) matrix with rows containing the 
%       vectors h(x(t+n),theta(induc)), where it is assumed that
%
%           E[ h(x(t+n),theta(induc)) | I(t) ] = 0,  t=1,...,nobs.
%
%       dH is a nobs x (m*length(induc)) matrix containing the 
%       derivatives of H with respect to the elements of theta(induc). 
%       See also GMMH.
%

%       Restricted case for:
%         Hansen, L.P. and K.J. Singleton, "Generalized Instrumental
%         Variables Estimation of Nonlinear Rational Expectations
%         Models," ECONOMETRICA, 50:1269-1286, 1982, pp. 1281-1282.

%

beta  = theta(1);
alpha = -1.19;

H=beta*xgmm(:,1).^alpha.*xgmm(:,2)-1;

if nargout>1;
  dH=(H+1)/beta;
end;