Most readers of this blog are probably familiar with Tobin's q. The idea is that if investment decisions are being made to maximize the wealth of shareholders, as theory and, sometimes, the law say they should be, then there should be a relationship between the value of financial claims on the firm and the value of its assets. Specifically, the former should be at least as great as the latter, since if investing another dollar in the firm does not increase its value to shareholders by at least a dollar, then that money would better have been returned to them instead.
As usual with anything interesting in macroeconomics, the idea goes back to Keynes, specifically Chapter 12 of the General Theory:
the daily revaluations of the Stock Exchange, though they are primarily made to facilitate transfers of old investments between one individual and another, inevitably exert a decisive influence on the rate of current investment. For there is no sense in building up a new enterprise at a cost greater than that at which a similar existing enterprise can be purchased; whilst there is an inducement to spend on a new project what may seem an extravagant sum, if it can be floated off on the Stock Exchange at an immediate profit. Thus certain classes of investment are governed by the average expectation of those who deal on the Stock Exchange as revealed in the price of shares, rather than by the genuine expectations of the professional entrepreneur.It was this kind of reasoning that led Hyman Minsky to describe Keynes as having "an investment theory of the business cycle, and a financial theory of investment." Axel Leijonhufvud, on the other hand, would warn us against taking the dramatis personae of this story too literally; the important point, he would argue, is the way in which investment responds to the shifts in the expected return on fixed investment versus the long-term interest rate. For better or worse, postwar Keynesians including the eponymous Tobin followed Keynes here in thinking of one group of decisionmakers whose expectations are embodied in share prices and another group setting investment within the firm. If shareholders are optimistic about the prospects for a business, or for business in general, the value of shares relative to the cost of capital goods will rise, a signal for firms to invest more; if they are pessimistic, share prices will fall relative to the cost of capital goods, a signal that further investment would be, from the point of view of shareholders, value-subtracting, and the cash should be disgorged instead.
There are various specifications of this relationship; for aggregate data, the usual one is the ratio of the value corporate equity to corporate net worth, that is, to total assets minus total liabilities. In any case, q fails rather miserably, both in the aggregate and the firm level, in its original purpose, predicting investment decisions. Here is q for nonfinancial corporations in the US over the past 60 years, along with corporate investment.
The obvious way of looking at this is that, contra Tobin and (at least some readings of) Keynes, stock prices don't seem to have much to do with fixed investment. Which is not so strange, when you think about it -- it's never been clear why managers and entrepreneurs should substitute the stock market's beliefs about the profitability of some new investment for their own, presumably better-informed, one. Just as well, given the unanchored gyrations of the stock market.
This is true as far as it goes, but there's another way of looking at it. Because, q isn't just uncorrelated with investment; for most of the period, at least until the 1990s, it's almost always well below 1. This is even more surprising when you consider that a well-run firm with an established market ought to have a q above one, since it will presumably have intangible assets -- corporate culture, loyal customers and so on -- that don't show up on the balance sheet. In other words, measured assets should seem to be "too low". But in fact, they're almost always too high. For most of the postwar period, it seems that corporations were systematically investing too much, at least from the point of view maximizing shareholder value.
I was talking with Suresh the other day about labor, and about the way labor organizing can be seen as a kind of assertion of a property right. Whether shareholders are "the" residual claimants of a firm's earnings is ultimately a political question, and in times and places where labor is strong, they are not. Same with tenant organizing -- you could see it as an assertion that long-time tenants have a property right in their homes, which I think fits most people's moral intuitions.
Seen from this angle, the fact that businesses were investing "too much" during much of the postwar decades no longer is a sign they were being irrational or made a mistake; it just suggests that they were considering the returns to claimants other than shareholders. Though one wouldn't what to read too much into it, it's interesting in this light that for the past dozen years aggregate q has been sitting at one, exactly where loyal agents for shareholders would try to keep it. In liberal circles, the relatively low business investment of the past decade is often considered a sign of something seriously wrong with the economy. But maybe it's just a sign that corporations have learned to obey their masters.
EDIT: In retrospect, the idea of labor as residual claimant does not really belong in this argument, it just confuses things. I am not suggesting that labor was ever able to compel capitalist firms to invest more than they wanted, but rather that "capitalists" were more divided sociologically before the shareholder revolution and that mangers of firms chose a higher level of investment than was optimal from the point of view of owners of financial assets. Another, maybe more straightforward way of looking at this is that q is higher -- financial claims on a firm are more valuable relative to the cost of its assets -- because it really is better to own financial claims on a productive enterprise today than in the pr-1980 period. You can reliably expect to receive a greater share of its surplus now than you could then.
[*] One of these days I really want to write something abut the investment boom of the 1970s. Nobody seems to realize that the highest levels of business investment in modern US history came in 1978-1981, supposedly the last terrible days of stagflation. Given the general consensus that fixed capital formation is at the heart of economic growth, why don't people ask what was going right then?
Part of it, presumably, must have been the kind of sociological factors pointed to here -- this was just before the Revolt of the Rentiers got going, when businesses could still pursue growth, market share and innovation for their own sakes, without worrying much about what shareholders thought. Part must have been that the US was still able to successfully export in a range of industries that would become uncompetitive when the dollar appreciated in the 1980s. But I suspect the biggest factor may have been inflation. We always talk about investment being encouraged by stuff that makes it more profitable for capitalists to hold their wealth in the form of capital goods. But logically it should be just as effective to reduce the returns and/or safety of financial assets. Since neither nominal interest rates nor stock prices tracked inflation in the 1970s, wealthholders had no choice but to accept holding a greater part of their wealth in the form of productive business assets. The distributional case for tolerating inflation is a bit less off-limits in polite conversation than it was a few years ago, but the taboo on discussing its macroeconomic benefits is still strong. Would be nice to try violating that.