Richard Cooper writes,

Development as a global policy objective dates from the 1940s. Relative to expectations then, the world economy performed outstandingly well during the second half of the 20th century.
Worldwide growth in average per capita income exceeded two percent a year (historically unprecedented), many poor countries became rich, infant mortality declined, diets improved, longevity increased, diseases were contained if not vanquished. Poverty on the World Bank
definition of $1 a day (in 1985$) declined dramatically, and the number of persons in poverty was halved despite a more than doubling of the world population.

Cooper’s point is that the state of the world’s economy should be measured not just against some improbable ideal but against reasonable expectations as of fifty years ago. The entire paper is worth reading. Thanks to Adam Smithee for the pointer.

Along similar lines, Ronald Bailey writes,

Even though some of the world’s poorest people are not earning much more than they were two generations ago, they’re still living much better than they were. In fact, many quality of life indicators are converging toward levels found in the richer countries.

Bailey cites the work of World Bank economist Charles Kenny, who points out that infant mortality and literacy have shown dramatic improvement in even the poorest countries.

For Discussion. What would be reasonable expectations for the state of the world economy fifty years into the future?