For the first time since 1917, then, we live in a world in which property rights and free markets are viewed as fundamental principles, not grudging … - Paul Krugman

So why did spatial issues remain a blind spot for the economic profession? It was not a historical accident: there was something about spatial economics that made it inherently unfriendly terrain for the kind of modeling mainstream economists know how to do. That something was, as you might well guess, the problem of in the face of increasing returns, a problem that is even more acute in than in . In development the crucial role that high assigned to increasing returns was a hypothesis crucial to that doctrine, but not necessarily crucial to understanding development in general. One could do meaningful theorizing about developing countries, albeit not in the grand tradition, without sacrificing the convenient assumptions of constant returns and perfect competition. In spatial economics, however, you really cannot get started at all without finding a way to deal with scale economies and oligopolistic firms.

What’s odd about Friedman’s absolutism on the virtues of markets and the vices of government is that in his work as an economist’s economist he was actually a model of restraint. As I pointed out earlier, he made great contributions to economic theory by emphasizing the role of individual rationality—but unlike some of his colleagues, he knew where to stop. Why didn’t he exhibit the same restraint in his role as a public intellectual?
The answer, I suspect, is that he got caught up in an essentially political role. Milton Friedman the great economist could and did acknowledge ambiguity. But Milton Friedman the great champion of free markets was expected to preach the true faith, not give voice to doubts. And he ended up playing the role his followers expected. As a result, over time the refreshing iconoclasm of his early career hardened into a rigid defense of what had become the new orthodoxy.
In the long run, great men are remembered for their strengths, not their weaknesses, and Milton Friedman was a very great man indeed—a man of intellectual courage who was one of the most important economic thinkers of all time, and possibly the most brilliant communicator of economic ideas to the general public that ever lived. But there’s a good case for arguing that Friedmanism, in the end, went too far, both as a doctrine and in its practical applications. When Friedman was beginning his career as a public intellectual, the times were ripe for a counterreformation against Keynesianism and all that went with it. But what the world needs now, I’d argue, is a counter-counterreformation.

When the economy is in a depression, scarcity ceases to rule. Productive resources sit idle, so that it is possible to have more of some things without having less of others; free lunches are all around. As a result, all the usual rules of economics are stood on their head; we enter a looking-glass world in which virtue is vice and prudence is folly. Thrift hurts our future prospects; sound money makes us poorer. Moreover, that's the kind of world we have been living in for the past several years, which means that it is a kind of world that students should understand. […] Depression economics is marked by paradoxes, in which seemingly virtuous actions have perverse, harmful effects. Two paradoxes in particular stand out: the , in which the attempt to save more actually leads to the nation as a whole saving less, and the less-well-known , in which the willingness of workers to protect their jobs by accepting lower wages actually reduces total employment. […] In times of depression, the rules are different. Conventionally sound policy—s, a firm commitment to —helps to keep the economy depressed. Once again, this is not normal. Most of the time we are not in a depression. But sometimes we are—and 2013, when this chapter was written, was one of those times.