Introduction The consumption-based model as a complete answer to most asset pricing question in principle, does not work well in practice; This observation motivates effects to tie the discount factor m to other data; Linear factor pricing models are most popular models of this sort in finance; They dominate discrete-time empirical work
General GMM formula Let y, be an h-vector of variables that are observed at date t, let denote an unknown vector of coefficients, h(e, y,) Be an r-vector real function. Let denote true value of 0, and suppose this true value is