Accounting for Growth With New Inputs

In this paper we examine how to account for growth when new inputs are being created. In particular, we obtain a decomposition of growth into that due to a higher quantity of existing inputs, and that due to a greater range of inputs. This decomposition is first obtained for a single firm, with a CES production function. We then generalize to the GNP function of an economy. and again show how a decomposition of growth in GNP can be obtained. An example is presented of a two-sector economy, where new inputs are endogenously created each period, and a simple aggregate production function exists. Data for this economy are simulated, and the GNP function is estimated using various different measures of the factor inputs.