There are two columns on important, big-picture topics at VoxEU today.

Martin Ravallion: The World Bank’s estimate of China’s real GDP per capita was revised down by 40% in 2005. This column explains how price surveys led to dramatically different estimates once they considered the effect of economic growth. It argues that while large revisions were needed, they could have been avoided with better economic models to measure PPPs.

Yiping Huang: Should the US follow Paul Krugman’s advice and use protectionist policies against China’s exports to encourage a revaluation of its currency? This column argues against this idea. Far from saving jobs, a revaluation of the Chinese currency might even cut global economic growth by 1.5%.