The Obama administration began with an embarrassment of economic talent, but the surfeit is disappearing. Larry Summers will step down as director of the National Economic Council at the end of the year. This follows the departure of Christina Romer from the Council of Economic Advisers and Peter Orszag from the Office of Management and Budget. The turnover creates an opportunity – one which, critics say, Barack Obama should seize. The president, they argue, needs an economic-policy reset.