LAST WORD The figure in the Last Word section shows that a 10-fold increase in a country’s GDP per person is associated with about a 20-point increase in EPI. Do you think that this pattern can be extrapolated out into the future?

That is, could the United States (which currently has an EPI of 78.5) gain another 20 points if it increased its GDP per person by a factor of 10 from its current level?

(Hint: Consider diminishing returns.)