Delong Explains Recessions

Brad Delong wrote a great post about why recessions happen. First he explains that inflation happens when there is more money than people need for managing market exchanges of goods and services,  and when there is too little money to be able to exchange all the goods and services that are wanted, a recession, or "general glut" happens.

Sometimes when you go the market, you find the money prices that you have to pay higher than you expected—perhaps 10% higher than you expected last year when you made your plans. It seems that, somehow, there is too much spending money chasing too few goods. How is this that this happens? And what should the government do to make sure that it does not happen?

Conversely, we can have the opposite problem—not a glut of money relative to goods, but what early-nineteenth century economists used to call a “general glut” of unsold commodities, idle factories and workshops, and idle workers all across the economy. Economists have important things to say about how to try to prevent these episodes and what to do when they happen to cure them. And this sixth role of economists as public intellectuals in the public square is worth going into in more depth.
Back in the 1820s the question of whether the circular flow of economic activity as mediated by the market system could break down and the economy become afflicted by a "general glut" of commodities was a live theoretical question. Everybody agreed that there could be particular gluts. Cosider what happens should households decide that they want to spend less on electricity to power large-screen video and audio entertainment systems and more on yoga lessons to seek inner peace. The immediate consequence—within the "market day," as late-nineteenth century British economist Alfred Marshall would have put it—of this shift in preferences is excess demand for yoga instructors and excess supply of electric power. Prices of electricity (and of large-screen TVs, and of audio systems) fall as unsold inventories pile up in stores and as generators spin down and stand idle. Yoga instructors, by contrast, find themselves overscheduled, working ten-hour days, and stressed out—and find the prices they can charge for their lessons going through the roof. Workers in electric power distribution and in video and audio production and sales find that they must either accept lower wages or find themselves out on the street without jobs.
Over time the market system provides individuals with changing incentives that resolve the excess-supply excess-demand disequilibrium. Seeing the fortunes to be earned by teaching yoga, more young people learn to properly regulate their svadisthana chakra and teach others to do so. Seeing unemployment and stagnant wages in electrical engineering, fewer people major in EECS. The supply of yoga instructors grows. The supply of electrical engineers shrinks. Wages of yoga instructors fall back towards normal. Wages of electrical engineers rise. And balanced equilibrium is restored. Thus we understand how there can be a glut of a particular commodity—in this case, electric power. And we understand that it is matched by an excess demand for another commodity—in this case, yoga instructor services to properly align your svadisthana chakra.
But can there be a general glut, a glut of everything?
Some economists early in the nineteenth century said yes. Other said that the idea of a "general glut" was logically incoherent. Jean Baptiste Say, for example:

Letters to Mr. Malthus: I shall not attempt, Sir, to add... in pointing out the just and ingenious observations in your book; the undertaking would be too laborious.... [And] I should be sorry to annoy either you or the public with dull and unprofitable disputes. But, I regret to say, that I find in your doctrines some fundamental principles which... would occasion a retrograde movement in a science of which your extensive information and great talents are so well calculated to assist the progress....
What is the cause of the general glut of all the markets in the world, to which merchandize is incessantly carried to be sold at a loss?... Since the time of Adam Smith, political economists have agreed that we do not in reality buy the objects we consume, with the money or circulating coin which we pay for them. We must in the first place have bought this money itself by the sale of productions of our own. To the proprietor of the mines whence this money is obtained, it is a production with which he purchases such commodities as he may have occasion for.... From these premises I had drawn a conclusion... “that if certain goods remain unsold, it is because other goods are not produced; and that it is production alone which opens markets to produce.”...
[W]henever there is a glut, a superabundance, [an excess supply] of several sorts of merchandize, it is because other articles [in excess demand] are not produced in sufficient quantities... if those who produce the latter could provide more... the former would then find the vent which they required...

Yet Say changed his mind. By 1829, in his analysis of the British financial panic and recession of 1825-6, Jean-Baptiste Say was writing that there could indeed be such a thing as a general glut of commodities after all: "every type of merchandise had sunk below its costs of production, a multitude of workers were without work. Many bankruptcies were declared..." The general glut, Say wrote in 1829, had been triggered by a panicked financial flight to quality in financial markets. What was going on? The answer was nailed by John Stuart Mill:

Those who have... affirmed that there was an excess of all commodities, never pretended that money was one of these commodities.... What it amounted to was, that persons in general, at that particular time, from a general expectation of being called upon to meet sudden demands, liked better to possess money than any other commodity. Money, consequently, was in request, and all other commodities were in comparative disrepute.... The result is, that all commodities fall in price, or become unsaleable.... [A]s there may be a temporary excess of any one article considered separately, so may there of commodities generally, not in consequence of over-production, but of a want of commercial confidence...

Note that these financial market excess demands can have any of a wide variety of causes: episodes of irrational panic, the restoration of realistic expectations after a period of irrational exuberance, bad news about future profits and technology, bad news about the solvency of government or of private corporations, bad government policy that inappropriately shrinks asset stocks, et cetera.
It seems as if there is always or almost always something that the government can do to affect asset supplies and demands that promises a welfare improvement over, say, waiting for prolonged nominal deflation to raise the real stock of liquid money, of bonds, or of high-quality AAA assets. Monetary policy open market operations swap AAA bonds for money. Quantitative easing that raises expected inflation diminishes demand for money and for AAA assets by taxing them. Non-standard monetary policy interventions swap risky bonds for AAA bonds or money. Fiscal policy affects both demand for goods and labor and the supply of AAA assets--as long as fiscal policy does not crack the status of government debt as AAA and diminish rather than increasing the supply of AAA assets. Government guarantees transform risky bonds into AAA assets. Et cetera...
And what if there is a glut not of commodities but inflation? Simply apply the same policy tools in reverse.
That is the last of the six things economists have to say in the public square: that the economy does not consistently balance itself at high employment with stable prices. The principle that it does economist have called Say’s Law—even though Say abandoned it by 1829. And it is important for economists to say, loudly, that Say’s Law is not true and theory, and it takes delicate and proper technocratic management to make it work in practice.