“Saving is mostly just delayed consumption, as generations of economists have taught, and the only way for capital to grow exactly at the interest rate is for nobody to consume it. Every bit of consumption pushes down the growth rate of capital.”
Garrett Jones, who has written a gently devastating review of a much-heralded book, Capital in the 21st Century, by someone called Thomas Piketty. The reason it is worth drawing attention to it is that this is the sort of book that you just know is going to get bandied about in the usual quarters as a source of supposed wisdom, when in fact its central contention is based on sand. In some ways, the claim that the rich get so proportionately rich that they gobble up the rest of us, so to speak, is hardly a new assertion. Piketty has repackaged it and added in new supposed facts to make the case.
Over to Jones:
There’s an extra reason to think that capital isn’t going to permanently grow at a faster rate than the overall economy: Piketty says it won’t. He places great weight on the mainstream economic idea that in the long run the natural tendency of market economies is for capital and the economy to both grow at the same rate, whatever that rate turns out to be. That “twin growth rate” might be high if population and technology are advancing quickly, or it might be low if both are in the doldrums, but there’s no inherent tendency for capital to outpace the economy forever, even when Piketty’s “central contradiction” of high interest rates holds.
The reason is simple. If the first machine is more productive than the second (i.e., diminishing returns), and if machines wear out and fall apart at a fairly predictable rate—a depreciation rate, in accounting-speak—then it’s a safe bet that in the long run capital and the economy will grow at about the same rate. Double the machines mean double the machines wearing out, so at some point you have so many machines (and houses and outdated software and office buildings) wearing out each year that a nation spends an enormous economic effort just replacing them. And of course if interest rates are high, business owners look for alternatives to capital (such as workers); private demand for capital thus shrinks. So growing replacement costs and the quest for cheaper alternatives both make it hard to imagine capital growing as far as the eye can see. I’ll spare you the math, but it’s getting harder all the time to see a central contradiction.
And then there is this paragraph, containing a nice little nugget:
But while Piketty’s contradiction is less an iron law and more a chalkboard speculation, there’s still plenty of room for class warfare in our future. A final way to see if capitalists are going to exercise unprecedented influence in the economy is to see whether their share of the economy is at unprecedented levels. Here, Piketty’s arduous historical research pays off. For the two countries for which he has data going back more than a century—Britain and France—the answer is clear: Capitalists are claiming a substantially smaller share of the economic pie today than they did in the mid-19th century. Back then capital income was a bit more than 40 percent of total national income. Now it’s a bit under 30 percent. So if capitalists—savers, landowners, entrepreneurs, and all the rest—are going to become a bigger deal in the future, they’ve got a long way to go before they’re at 19th-century levels. (Emphasis added to original.)
The author is fair in pointing out that there are useful insights in the book, although given that its central contention appears to be a crock, that is not a lot of praise.