The financial worries of New York City in the early 1970s began registering in the bond market in October 1974, when the city first encountered difficulty selling its securities. These problems reached a crisis stage in 1976, and it was not until then that the bond rating services reduced the city’s bond rating. In this and other cases, the bond rating did not anticipate the crisis but underwent adjustment only after the reality had become evident.

A version of this article appeared in the July 1980 issue of Harvard Business Review.