The role of government in ensuring markets are sufficiently competitive to put an economy’s resources to their best use has always shifted according to prevailing political tides. This week the Department of Justice duly announced a significant change in its approach to antitrust law. Out goes the belief companies are best left to thrash things out themselves. In comes the view that unbridled competition cannot be relied on to tackle over mighty businesses that abuse their monopolistic powers.

Some argue the laisser faire Bush administration was simply out to help its corporate friends. Compared with the Clinton years, during which the DoJ aggressively went after Microsoft, American Airlines and Visa, for example, competition lawyers have for much of this decade been twiddling their thumbs. According to the Center for American Progress, there was a five-year stretch when no merger cases were brought to court at all.