Crime goes down

Monday, June 16, 2008

Both violent and property crimes declined in the U.S. in 2007 from the previous year, the FBI recently reported.

The news gives us reason for modest optimism. The optimism is only modest because it is uncertain whether the crime decline, 1.4 percent for violent crimes and 2.1 percent for property crimes, represents a trend or is simply the normal fluctuations seen from year to year in a situation that is basically stable. The decline followed two years of increased in crime.

FBI spokesman Richard Kolko acknowledges the difficulty in drawing long-term conclusions from the latest statistics.

"One preliminary report does not make a trend, but it's going the way we want it to go," he said.

News media being what they are, anything that is reported needs to be regarded as significant in order to justify reporting it.

This seems particularly true in reporting the fluctuations in the annual results on comprehensive tests for high school academic knowledge. A fraction of point difference from the previous year appears to be cause for either unbridled joy or deep despair.

Many statistical comparisons need to be taken with a grain of salt.