As David Bayley, noted criminologist, mentioned in 1994, “The police do not prevent crime. This is one of the best kept secrets of modern life. Experts know it, the police know it, but the public does not know it.”
Some economists were still cynical based on intuition. In reality though, their empirical work during that time were combined with a few files displaying some or no impact of police on crime. However, since the pioneering study of Levitt, several papers have applied an array of more reliable research techniques, including matching, natural experiments and regression discontinuity.
If based on individually, any one of these researches are subject to objections. As a group though, their findings have been unusually consistent – police lower crime with a 10 percent surge in police lowering property crime by around three to four percent and violent crime by nearly four to five percent.
Because of these, a couple of studies begged to prove a point. The University of Pennsylvania consists of a massive private police force of nearly 100 officers patrolling the Penn Campus and a considerable portion of the adjoining neighborhood. The city police also guard the Penn neighborhood, but the UP police only cover a known area. This is why there are a lot more authorities on the Penn side than on the other border.
MacDonald, Kick and Grunwald integrated regression discontinuity to discover the crime rates around the border region. They learned that crime rates drop the closer it is to the border.
Calculations regarding the resistance of crime with consideration to the police are mainly consistent throughout the several researches, which prove how credible the new techniques are. The resistance calculations are also essential as their size suggests that major policy changes could enhance social welfare. The empirical economics of crime is one of the most beneficial parts of economics in which considerable improvements have happened in the recent years.