Jeremy Grantham Goes Malthusian

From Business Insider, JEREMY GRANTHAM: We're Headed For A Disaster Of Biblical Proportions

Specifically, Grantham says, the phenomenon of ever-more humans using a finite supply of natural resources cannot continue forever--and the prices of metals, hydrocarbons (oil), and food are now beginning to reflect that.

Now, I'm not as learned as Mr. Grantham, but I disagree. There are substitutes for metals and hydrocarbons, and anyone who has driven across the United States can tell you that we're nowhere near running out of capacity to grow more food.

Then again, the switch to substitutes takes time, as does bringing online new food production capacity. In the mean time, if demand significantly outstrips supply, things could get ugly.

Homo economicus?

From How, and When, to Make a Decision in The Economist's More Intelligent Life magazine:

If all our decisions are so influenced by external factors, that raises an inevitable question: to what extent are we involved in our own decision-making? Professor Ackerman believes the answer is very little: “All of these subtle influences suggest that most of what is causing our behaviour we are really not aware of. People are just very good at post-hoc reasons for their behaviour.

Tastes and preferences, mentioned and then immediately set aside in most microeconomics courses, seem to me to be the overriding inputs in almost all personal decisions. Marketers figured this out a long time ago. What's taking economists so long?

ZMP's Revisited

Tyler Cowan, following up on last summer's discussion of Zero Marginal Product workers (ZMP's, as he calls them), offers a proof point:

People unemployed over 6 months rose by a whopping 361k, 44% of all unemployed.

But again, unless each worker's productivity remains constant over time (it doesn't) it doesn't follow that the currently unemployed weren't productive when they were working. It could just be that the currently employed are working harder, which stands to reason.

ZMP's indeed. ZMV econ bloggers maybe.