Technologies and their diffusion intensity

Marginal Revolution points to the work of Diego Comin and Marti Mestieri, who document the trends associated with the diffusion of 25 technologies in 139 countries over the past two centuries, and posit an explanation for cross-country differences in income growth over the long-term. They focus on two distinct margins of adoption that are specific each technology and country, the adoption lag and the intensity of use.

They simulate a model to study the effect of technology diffusion process on the productivity growth,

Adoption lags have converged across countries, while the intensity of use has diverged... Our simulations have shown that differences in technology diffusion patterns account for a major part of the evolution of the world income distribution over the last two centuries. In particular, differences in the evolution of adoption margins in Western and non-Western countries account for around 75% of the income per capita divergence observed between 1820 and 2000... First, our findings show that the majority of the divergence in productivity can be accounted for by technology diffusion. Second, the critical dimension of technology diffusion to understand the divergence in productivity is the intensity of use of technology. Third, economy-wide factors such as exogenous TFP not only played a minor role in explaining cross-country productivity dynamics. They also played a minor role in explaining differences in the evolution of technology diffusion across countries...

The average estimated adoption lag is 42 years. The average intensity of adoption in Non-Western countries is half (47%) of the level of Western countries. We document significant dispersion on both margins of adoption across countries and technologies. For example, comparing the 90th to the 10th percentiles of our estimates, we find 10-fold differences in adoption lags and 8-fold differences in the intensity of adoption.

Nice summary from Tyler

The mean adoption lag for spindles, classified as a 1779 technology, was 130 years, or in other words that is how long it took for the technology to move to poorer countries. For ships, listed as a 1788 technology, the mean lag is 110 years. Synthetic fiber is a 1931 technology, with a mean adoption lag of 29 years. For the internet, a 1983 technology (is that right?), the mean adoption lag is only 6 years. But the overall story is not so simple. The more advanced countries use more of these technologies, and use them more effectively (“intensity”), and that gap has been growing over time. Yes, Ghana has the internet, but it is Silicon Valley that is working wonders with it. Some technology use begs more technology use.