Laws can be an important source of economic efficiency – or inefficiency. Early economists such as Adam Smith often wrote about the economic impact of legal matters. But economics subsequently focused more narrowly on things monetary and commercial. It was only in the 1940s and 1950s, at the University of Chicago Law School, that the discipline of law and economics was born. It is now a substantial branch of economics and has had an impact beyond the ivory towers. The "economics" of law and economics is firmly in the liberal economics camp, favoring free markets and arguing that regulation often does more harm than good. It stresses the economic value of having clear, enforceable property rights, and of ensuring that these can be bought and sold. It has encouraged many antitrust policy¬makers to focus on maximizing consumer welfare, rather than, say, protecting small firms or opposing big ones just because they are big. It has also ventured into broader sociological issues, for instance, analyzing the economic causes of criminality and how to structure legal incentives to reduce crime. (See also evolutionary economics. )