Reversion to mean

Echoing recent comments by Vitaliy Katsenelson (also on Barron's), Jeremy Grantham thinks profit margins will decline towards normal and the Standard & Poor's 500 will head from its current c. 1334 to 1100 in the year 2010 - a drop of about 18%.

Grantham is emphatic that borrowed money is not a stimulant to the economy:

I have an exhibit that shows the 30 years prior to 1982 when the debt-to-gross domestic product ratio was completely flat at 1.2 times. Total debt is defined as government debt, personal debt, corporate debt and financial debt. Then in the 25 years after 1982, the flat line goes up at a 45 degrees angle from 1.2 times to 3.1 times GDP. Massive. In the first 30 years, when debt is flat, annual GDP growth is its usual battleship, growing at 3.5% and hardly twitching. After the massive increase in debt, GDP, far from accelerating, grew at 3%. So debt in the aggregate does not drive the economy. The economy is driven by education, man-hours worked, capital investment and technology.

That last sentence is really pregnant. I'm not sure about the man-hours (the closer we approach peasanthood, the harder we'll work), but I think that on both sides of the Atlantic, we've been falling down on the other three.

In Britain, our government has failed to distinguish between investing in education, and managing it - and where it has tried to do the latter, has pursued a Romantic-heritage political agenda. Capital investment? Going abroad. Technology? Ditto - and eagerly taken up (if not positively filched) by our Eastern trading partners.

I live in what used to be Car City; now, the vast Longbridge site is being redeveloped for housing and shops - in other words, open prison for the new ex-industrial underclass.

But Rome, too, kept control of its plebs with bread and circuses for a couple more centuries, before it fell.

Why equities should go down

I'm breaking radio silence because of a brilliantly lucid article (from the subscription-only Barron's site) found for us by Michael Panzner.

Vitaliy Katsenelson explains that the current average price-earnings ratio may seem cheap, but that's because recent profit margins have been well above the 8.5% trend. Even allowing for a shift since 1980 away from industry towards the higher-margin service sector, the present 11.9% profit margin should be seen against a longer-term background figure of around 8.9 - 9.2%, which if current p/e ratios continue would imply a downward stock price correction of 22 -25%.

This chimes with Robert McHugh's "Dow 9,000" prediction from last July. And in many fields it's usual for overshoot to occur in the process of regression to a mean, so if it holds true in this case we could see even deeper temporary lows.

Day traders, be warned: this piste is a Black Run.