Harvard's Sendhil Mullainathan's Unintended Consequences in the New York Times: "Ban the Box? An Effort to Stop Discrimination May Actually Increase It"

Policies aimed at ending discrimination against people with criminal records may actually have the unintended consequence of increasing racial discrimination. That, at least, is the finding of a fascinating new study that focused on so-called ban the box regulations — rules that prohibit initial job applications from asking prospective employees to check a box indicating whether they have a criminal history.

Before the regulations took effect, candidates with criminal histories were far less likely to be called back, irrespective of race. After the regulations took effect, though, things changed. Lacking the ability to discern criminal history, employers became much less likely to call back any apparently black applicant. They seemed to treat all black applicants now as if they might have a criminal past. These were big and disheartening effects: Banning the box extended discrimination to virtually all black applicants.

I like his succinct definition of the unintended consequences:

This pernicious result is the economists’ law of unintended consequences. Policy makers can constrain only a few of the large spectrum of choices people make. If motives remain unchanged, there remain many unregulated ways of expressing them. For example, when landlords find that their properties have risen in value, they may want to raise the rent. If the government imposes rent control, landlords find other ways to increase revenue. This is also a challenge in fighting discrimination: When we try to curb certain behaviors, the underlying discriminatory impulse manifests itself elsewhere. If we prevent lenders from screening out African-Americans, they might avoid lending to whole neighborhoods.