The suicide of Princeton economist Alan Krueger earlier this month is a reminder that self-harm remains an American health crisis and that professional success in no way insulates people from the danger. Mr Krueger, after all, had served as chairman of the Council of Economic Advisers under former president Barack Obama and was widely viewed as one of the leading labour economists of his (or any) generation.

The data suggests that white and middle-aged Americans are the demographic groups most at risk for suicide. So in one sense, Mr Krueger's tragedy fits the prevailing pattern - as did the deaths last year of celebrity chef Anthony Bourdain and fashion designer Kate Spade. In general, suicide rates among whites are about three times higher than for blacks and Latinos.