Tyler Cowen and Alex Tabarrok have a new Macro textbook, and it sounds awesome. It actually prioritizes incentives. Incentives-based approaches basically apply the assumption of individual self-interest and looks at the implications. That's Adam Smith's insight, and he's the father of economics. The father of macroeconomics has not generated similarly fruitful insights. Since Keynes macro has focused on aggregate accounts and indices, operating according to laws of motion. Sure, you might motivate the laws via a consumer maximizing his lifetime income, but that's all throat clearing for estimating equations where aggregate amounts C, G, I, and X interact with monetary variables P, i, and M in some dynamic feedback loop
The hope was that macroeconomics would be like physics, where you have laws at a lower level, and unrelated laws at a higher level. In 1972, Philip Anderson, who won the Nobel prize in physics for his work on superconductivity, wrote an article titled “More Is Different,” and contended that particle physics, and indeed all reductionist approaches, have limited ability to explain the world. Reality has a hierarchical structure, but that does not mean one should always try to explain one layer from deeper layers.
At each stage entirely new laws, concepts, and generalizations are necessary, requiring inspiration and creativity to just as great a degree as in the previous one. Psychology is not applied biology, nor is biology applied chemistry.
No collective organizational phenomenon, such as crystallization and magnetism, has ever been deduced from its lower-level parts. Emergent phenomenona render reductionist views irrelevant for explaining phenomena at that level—it is unhelpful to try to understand cancer through mere chemistry, or worse, particle physics. But that does not mean that chemistry, or particle physics, is uninteresting, just, at one level, not so much.
Unfortunately, macro economics has not generated comparable emergent properties in macroeconomic time series. Incentive matter a great deal on the macro level, even if they are more difficult to reify than something like total consumption or the money supply. The stagnation of socialist economies was not predicted by 1950's economists, indeed most economist thought capitalism was merely superior in liberty, not growth or prosperity. The thought the economy was like a big input-output matrix, and with centralized planning combined with forced savings, the Soviet Economy seemed sure to overtake the West. But this turned out quite wrong because people in a position to make decisions did not have the right incentives. I don't know exactly how Cowen and Tabarrok handle this in their text, but a good assumption goes a long way, and moving from textbooks with price-stickiness models, or government multipliers, to starting with incentives, is a first-order step in a better direction.
They mentioned they address the current financial crisis, and though I'm sure there's a demand, with so much new information coming out, and the fate--if not the current condition--of banks so uncertain, I sense that section will be much rewritten if there is a second edition. In any case, mazel tov, gentlemen!