A study was performed looking at the relationship between economic growth as measured by GDP in the previous year and equity returns this year. In both developed and emerging markets, average annual returns were similar for high and low growth countries. In fact, low growth countries had slightly higher average returns than high growth countries, although this return difference was not reliably different from zero. In other words, there is no evidence that this return difference occurred by anything other than random chance.See the actual report with graphs and tables here.