Understanding the Great Recession

Here is a short summary of a proposed explanation of the current economic collapse. This is a bit from a post by UC Berkeley economist Brad DeLong:

As I understand the Greenwald-Stiglitz hypothesis--about the Great Depression as applied to agriculture and about today as applied to manufacturing--it goes like this:

1. Rapid technological progress in a very large economic sector (agriculture then, manufacturing now) leads to oversupply and steep declines in the sector's prices. Poorer producers have less income. They come under pressure to cut back their spending. Others--consumers--are now richer because they are paying less for their food (or their manufactures), but their propensity to spend is lower than that of the stressed farmers or ex-manufacturing workers.


2. Moreover, the oversupply of agricultural commodities (or manufactured goods) means that only an idiot would invest at their normal pace in those sectors. To the shortfall in consumption spending is added a shortfall in investment spending as well.


3. Thus we have systematic pressures pushing spending down below economy-wide income. These aren't going to go away until the declining sector (agriculture then, manufacturing now) is no longer large enough to be macroeconomically significant.


4. Macroeconomic balance requires that the economy generate offsetting pressures pushing spending up. What might they be?


5. For a while, those receiving the income that farmers (or ex-manufacturing workers) have lost and those who use to invest in the declining sectors can lend it to the farmers (or ex-manufacturing workers) so that they can keep up with the Joneses. But lending more and more to poorer and poorer debtors is, like lawn darts, only all fun-and-games until somebody loses an eye.


6. An alternative possibility is to switch investment away from the farm value-chain complex (or the manufacturing value-chain complex) to something else. But what? Nobody really knows. The future is uncertain. Other investments are clearly riskier then funneling money into the old channels of boosting the capital of the farm value-chain complex (or the manufacturing value-chain complex) had been. Given the extra risks, this pressure can only manifest itself if the cost of capital falls. But here we hit the zero lower bound on interest rates. And we are off to the secular liquidity-trap races. This won't work either.

A very readable presentation of the thesis is in a Vanity Fair article by Nobel prize-winning economist Joseph Stiglitz.