We document that rating agencies have become more conservative in assigning ratings to corporate bonds over the period 1985 to 2009. Holding firm characteristics constant, average ratings have dropped by 3 notches (e.g., from A+ to BBB+) over time. This increased stringency has affected both...

We show that rating agencies have become more conservative in assigning credit ratings to corporations over the period 1985 to 2009. Holding firm characteristics constant, average ratings have dropped by three notches (e.g., from A to BBB ) over time. Consistent with the view that this change...