Doug Henwood, in his book Wall Street, argues that the q ratio fails to accurately predict investment, as Tobin claims. "The data for Tobin and Brainard’s 1977 paper covers 1960 to 1974, a period for which q seemed to explain investment pretty well," he writes. "But as the chart [see right] shows, things started going away even before the paper was published. While q and investment seemed to move together for the first half of the chart, they part ways almost at the middle; q collapsed during the bearish stock markets of the 1970s, yet investment rose." (p. 145)
To me this is no criticism at all. What good is a metric that tracks the average? If it is up, it tells you that the market is up. If it is down, it tells you that the market is down. Hooray! What
can be helpful over the long term is a metric that is mean reverting, but has a variable pul back toward some central value.
Clearly a leveraged or short swing trader would want nothing to do with Q. It could be getting us in now at an early point, and as many of the board members have pointed to in the past, this and similar value metrics would have got us out in the mid 90s, a time of huge market gains. It is not for speculators.
I myself made some of my best investments when Q was high in the late 90s- but they were not the popular stocks. Some high quality companies were remarkably cheap when the S&P and NASDAQ were going wild.
Over time, value trumps all. If you are an individual stock investor, value is where and when you find it. But for index or CEF or mutul fund investors, just a look at that chart shows that a low Q is correlated with low risk and high return potential times for investing. I don't think it is near as good at announcing when to be out. Markets have natural bottoms. If things get cheap enough, management buyouts, LBOSs, strategic and foreign takeovers all tend to limit the low- since if you can buy something cheaper on Wall Street, whey go out and build it?
But there is really no limit to craziness on the upside, as those of us who were old enough to observe the 90s know quite well.
Ha