We introduce a tractable model of endogenous growth in which the returns to innovation are determined by the technology … adoption decisions of the users of new technologies. Technology adoption involves an implementation investment that determines … the initial productivity of a new technology. After implementation, learning increases the productivity of a technology to …

as they are used in the countries in our sample. We denote these time lags as technology usage lags and compare them with … lags in real GDP per capita. We find that (i) technology usage lags are large, often comparable to lags in real GDP per … they replace combined with the usage lags that we document, lead us to infer that technology usage disparities might …