1 Erratum

After publication of (Valletta 2014), it emerged that a number of errors had been introduced into the article due to a publisher error. Most importantly, in Table 5, the coefficient entry in the first row of Panel B, column (2), should have a negative sign in front of it (“-0.00514*”). Other errors largely pertain to display labeling and alignment and have been left as is for simplicity. Springer would like to apologize for any inconvenience caused.