The Rational Optimist (P.S.)

by Matt Ridley

It was Paul Romer’s great achievement in the 1990s to rescue the discipline of economics from the century-long cul-de-sac into which it had driven by failing to incorporate innovation. From time to time its practitioners had tried to escape into theorems of increasing returns – Mill in the 1840s, Allyn Young in the 1920s, Joseph Schumpeter in the 1940s, Robert Solow in the 1950s – but not until Romer’s ‘new growth theory’ in the 1990s was economics fully back in the real world: a world where perpetual innovation brings brief bursts of profit through temporary monopoly to whoever can commandeer demand for new products or services, and long bursts of growth to everybody else who eventually gets to share the spilled-over idea. Robert Solow had concluded that innovation accounted for growth that could not be explained by an increase in labour, land or capital, but he saw innovation as an external force, a slice of luck that some economies had more of than others – his was Mill’s theory with calculus. Things like climate, geography and political institutions determined the rate of innovation – which is bad luck for land-locked tropical dictatorships – and not much could be done about them. Romer saw that innovation itself was an item of investment, that new, applied knowledge was itself a product. So long as people who are spending money on trying to find new ideas can profit from them before they pass them on, then increasing returns are possible.