in goods and services has expanded steadily over the past six decades thanks to declines in shipping and communication costs, globally negotiated red… - Paul Krugman

Economics is harder than physics; luckily it is not quite as hard as sociology. Why is economics such a hard subject? Part of the answer has to do with complexity. The economy cannot be put in a box. [...] Another reason economics is hard is that the critical sociologist is right: it involves human beings, who do not behave in simple, mechanical ways.

If we discovered that, you know, space aliens were planning to attack and we needed a massive buildup to counter the space alien threat and really inflation and budget deficits took secondary place to that, this slump would be over in 18 months. … There was a Twilight Zone episode like this in which scientists fake an alien threat in order to achieve world peace. Well, this time, we don't need it, we need it in order to get some fiscal stimulus.

The irony... is that high development theory was right. By this I do not mean that the Big Push is really the right story of how development takes place, or even that the issues raised in high development theory are necessarily the key ones for making poor countries rich. What I do mean is that the unconventional themes put forth by the high development theorists—their emphasis on strategic complementarity in investment decisions and on the problem of coordination failure—did... identify important possibilities that are neglected in models. But the high development theorists failed to convince their colleagues of the importance of those possibilities. Worse, they failed even to communicate clearly what they were talking about. And so good ideas, important ideas, were ignored for a generation...