Productivity in Process - this week in the Economist - Economics Focus

The Economist this week discusses research by my old college friend Tim Leunig (LSE) and myself on process innovations - that's two Econ Focus highlights in three weeks... Here is the abstract of the paper (available on SSRN):

Fifty years ago economic historians found surprisingly small gains from 19th century US railroads, while more recently economists have found relatively large gains from electricity, computers and cell phones. In each case the implicit or explicit assumption is that researchers were measuring the value of a new good to society. In this paper we use the same techniques to find the value to society of making existing goods cheaper. Henry Ford did not invent the car, and the inventors of mechanised cotton spinning in the industrial revolution invented no new product. But both made existing products dramatically cheaper, bringing them into the reach of many more consumers. That in turn has potentially large welfare effects. We find that the consumer surplus of Henry Ford’s production line was around 2% by 1923, 15 years after Ford began to implement the moving assembly line, while the mechanisation of cotton spinning was worth around 6% by 1820, 34 years after its initial invention. Both are large: of the same order of magnitude as consumer expenditure on these items, and as large or larger than the value of the internet to consumers. On the social savings measure traditionally used by economic historians, these process innovations  were worth 15% and 18% respectively, making them more important than railroads. Our results remind us that process innovations can be at least as important for welfare and productivity as the invention of new products.