This paper presents a critical assessment of the development of economic models of oil supply projection over the last two decades. The survey illustrates the fact that although most models have stressed the significance of the economic variables in the supply function, few attempts have been made to incorporate technology as a variable. Although such an approach can be justified under certain special circumstances, it is considered unsuitable as a supply forecaster in the increasingly numerous marginal fields where operations approach the technology frontier. In this connection, the latter part of the paper discusses the possibility of and problems associated with incorporating technology as a variable in the projection of supply. © 1980 John Wiley & Sons, Ltd.