19 June 2019

It is natural to assume that a country’s share market performance is driven by its economic performance, and therefore that a country with high GDP growth will generate high equity returns. Unfortunately, completely the opposite is true. For most countries over most periods, equity returns are negatively correlated with economic growth. How could this happen?

We have known for four decades that share markets are much more volatile than they ought to be if their price movements were driven by changes in economic and business fundamentals alone. Robert Shiller pointed out in 1981 that, based on price and dividend data since 1871, share price volatility was more than five times the level you would expect if prices responded only to new information about future dividends or real interest rates. This conclusion suggested that more than 80% of share price movements were mere noise, unrelated to fundamental information. Or, as Paul Samuelson joked, “The share market has predicted nine of the last five recessions.”… [read more]