Crime is a subject on which people have strong opinions. Some believe society creates criminals; others think the prison system is at fault. Others still say it is individuals who are to blame. The truth is that we don’t really know what makes people turn to crime, but it seems likely that it is a combination of the above factors, rather than a single cause. There is, however, one thing we can be sure of: when crime falls—something which admittedly doesn’t happen very often—every politician around will claim credit for it. President Clinton was the first to do so. During the American Presidential campaign in 1996, he claimed his government was responsible for falling crime rates in the U.S. which had been dropping for five years in a row. "We are making a difference," he declared "our neighborhoods are safer, and we are bringing back the American People’s confidence that crime can be reduced." At first sight, one might be tempted to believe him, particularly if one looks at the situation in New York. Here, many neighborhoods which used to be crime-ridden are certainly safer. Last year, fewer than 1000 people were killed in the Big Apple. This is the lowest recorded number since 1968, and less than half the number recorded in 1990, when 2245 died as a result of crime. But while President Clinton was busy claiming credit for reducing crime across the country, New York’s Republican mayor, Rudolph Giuliani was quick to point out that his "zero-tolerance" policy was the reason crime rates in New York were falling. "Zero-tolerance" works on the principle that smaller crimes lead to bigger offences. This policy has, according to Mayor Giuliani, sent a message to more serious criminals. What does "the Big Apple" (Para. 3) refer to