Bull market blues: Trying to make sense of Wall St.

Like most economists, I don’t usually have much to say about stocks. Stocks are even more susceptible than other markets to popular delusions and the madness of crowds, and stock prices generally have a lot less to do with the state of the economy or its future prospects than many people believe.

Still, we shouldn’t completely ignore stock prices. The fact that the major averages have lately been hitting new highs — the Dow has risen 177 percent from its low point in March 2009 — is newsworthy and noteworthy. What are those Wall Street indexes telling us?

The answer, I’d suggest, isn’t entirely positive. In fact, in some ways the stock market’s gains reflect economic weaknesses, not strengths. And understanding how that works may help us make sense of the troubling state our economy is in.

Let’s start with the myth that stock prices are the measure of the economy as a whole. That myth used to be popular on the political right, with prominent conservative economists publishing articles with titles like “Obama’s Radicalism Is Killing the Dow.”

Strange to say, we began hearing that line a lot less once stock prices began their huge surge — just six weeks after President Obama was inaugurated. (But polling suggests most Republicans still believe stocks have gone down in the Obama era.)

The truth, in any case, is that there are three big points of slippage between stock prices and the success of the economy in general. First, stock prices reflect profits, not overall incomes. Second, they also reflect the availability of other investment opportunities — or the lack thereof. Finally, the relationship between stock prices and real investment that expands the economy’s capacity has gotten very tenuous.

On the first point: We measure the economy’s success by the extent to which it generates rising incomes for the population. But stocks don’t reflect incomes in general; they only reflect the part of income that shows up as profits.

On the second point: When investors buy stocks, they’re buying a share of future profits. What that’s worth to them depends on what other options they have for converting money today into income tomorrow.

Also, these days profits often seem to bear little relationship to investment in new capacity. Instead, profits come from some kind of market power — brand position, the advantages of an established network, or good old-fashioned monopoly. And companies making profits from such power can simultaneously have high stock prices and little reason to spend.

Consider the fact that the three most valuable companies in America are Apple, Google and Microsoft. None of the three spends large sums on bricks and mortar. In fact, all three are sitting on huge reserves of cash. When interest rates go down, they don’t have much incentive to spend more on expanding their businesses; they just keep raking in earnings, and the public becomes willing to pay more for a piece of those earnings.

In other words, while record stock prices do put the lie to claims that the Obama administration has been anti-business, they’re not evidence of a healthy economy. If anything, they’re a sign of an economy with too few opportunities for productive investment and too much monopoly power.

So when you read headlines about stock prices, remember: What’s good for the Dow isn’t necessarily good for America, or vice versa.