A small but significant nationwide drop in crime also preceded Giuliani's election, and continued throughout the 1990s.

Criminologists say the decline in New York has contributed substantially to the nationwide statistical drop in crime.

Contributing to the decline, she said, were a nationwide drop in international visitors, a faltering economy and "the self-inflicted wound" of the Broadway musicians' strike in March.

The nationwide drop in the number of death sentences is the product of several phenomena, including a lower murder rate.

The report also showed that the city experienced a 4.3 percent drop in overall reported crime last year compared with a nationwide drop of 1.2 percent.

A small nationwide drop in crime preceded Giuliani's election, and critics say that he may have been the beneficiary of a trend already in progress.

Experts say they believe these incidents do not mean that the nationwide drop in crime since 1992 is illusory.

The nationwide drop in oyster consumption, from 75 million pounds in 1956 to 33 million in 1993, may also have to do with changing American tastes.

The F.B.I. said the nationwide drop was about 3 percent.