The recent history of economic growth

In a commentary for the American Enterprise Institute, Ryan Streeter criticizes gatherings like the World Economic Forum. Streeter says instead of all the talk at the WEF about redesign and change to boost economies, we should look back at the growth that the world has experienced in the last 40 years.

How ironic, then, that just prior to their gathering, Maxim Pinkovskiy and Xavier Sala-i-Martin updated findings from their 2009 National Bureau of Economic Research paper, “Parametric Estimations of the World Distribution of Income,” on the economics website VOX. Their findings show precipitous drops in global poverty since 1970—just about the same time WEF began meeting in Davos (Mark Perry wrote about the original paper here).

Between 1970 and 2006, the global poverty rate fell nearly 75 percent. During this period, the percentage of the world’s population living on less than a dollar a day fell from 26.8 to 5.4 percent. The world’s population grew 80 percent during the same period, which makes the poverty reduction all the more astounding. The global Gini coefficient, a standard measure of inequality, fell from 67.6 to 61.2 percent, indicating a drop in inequality as well as poverty. The same trend is found in other measures of inequality besides Gini.

And when one computes a measure of global “welfare” understood in the old-fashioned sense of well-being, we find that life has gotten better faster for a larger share of the world’s population than perhaps any time in history. By deriving a calculation of well-being from GDP and inequality measures, the authors show that between 1970 and 2006, global welfare more than doubled, growing faster than GDP.

The authors also consider the World Bank’s new purchasing power parity (PPP)–adjusted measures of GDP and find that while global poverty increases overall, the rate of poverty actually drops faster since 1970 than it does under more conventional GDP measures. In other words, under the PPP model, the world looks a lot poorer in 1970 than it does using more traditional measures of poverty, but today, the poverty rate is nearly the same regardless of whether one uses the PPP or more traditional measures (see the graph below). Using the World Bank’s adjustment actually has the effect of making it look like we have been doing a better job of reducing poverty over the past three decades, despite how the world looks poorer in any given year.