COMPUTATION OF MAXIMUM-LIKELIHOOD-ESTIMATES OF GRAVITY MODEL PARAMETERS

This paper presents the derivations of several new algorithms for the computation of maximum likelihood estimates of the parameters of a very general form of the gravity model. The algorithms are then compared with previously available algorithms including GLIM and that given in Sen (1986). One of the new algorithms emerges ar, far superior in just about every way to its competitors. In particular, it is usually much more than an order of magnitude faster than the GLIM procedure and that given in Sen (1986). It is also not substantially affected by pitfalls such as multicollinearity and (unlike the GLIM procedure) is capable of comfortably handling large O-D matrices.