Since its inception the Research unit has been involved to a significant extent in econometric model building, sometimes with the objective of estimating prices or quantities of agricultural commodities. Thus for example over the last two years we have contracted to estimate the price of New Zealand wool for the ensuing season. Initially this led us to review available techniques and in particular to explore further the Box-Jenkins and leading indicator approaches. Joan Rodgers and Les Woods have been associated with much of this work. We now consider it appropriate to draw together our literature reviews and working papers, add some empirical material and publish for a wider audience.