Productivity growth is often cited as one of the major factors contributing to the continued economic growth of the postwar agricultural sector. Approaches to the measurement of productivity growth and technical change may be grouped into two broad categories: (a) analyses for which a change in total factor productivity is interpreted as the rate of change of an index of aggregate output divided by an index of aggregate input or (b) analyses which involve estimating the rate of shift of production relations. To compare the empirical measures resulting from the two approaches and to de¬compose productivity growth into compo¬nents associated with scale and technical change, one needs to understand the assump¬tions and methodology underlying each ap¬proach. For example, in constructing a measure of total factor productivity (TFP) growth based on the divisia indexing procedure, the rate of growth of inputs and outputs are weighted by their average cost shares and revenue shares, respectively. This index of TFP growth is equivalent to a measure of the rate of technical change if we assume that there are competitive markets and constant-retums-to- scale technology