Wednesday, November 14, 2007

The price of oil is telling us something

The record levels that oil price has recently hit is surprising; the fact that oil price has been rising over time, is not. Way back in 1931, the economist Harold Hotelling argued that prices of exhaustible resources should be rising over time. His fundamental equation (in modified form) states that:

Growth rate of net resource price = discount rate.

The net resource price is simply the market price of the resource, less the marginal cost of extraction. The discount rate is the "rate of time preference". It is the amount by which the subjective value of one peso falls if it is received next period, rather than now. This can be proxied by the interest rate. An alternative way to express this is:

Net resource price now = (1 + discount rate) x (Net resource price last period).

Extracting one unit of the resource now rather than a while ago, requires that the net price now exceed the previous net price by the rate of time preference. If the marginal cost of extraction is constant, then the net price will rise only if the market price rises.

Short-run price increases can be explained by rising demand, or rising marginal costs of extraction, or both. Because of this, the oil market appears to have undergone a permanent upward shift in the trend line. Speculative forces also introduce short-term volatility in oil prices. Nevertheless, Hotelling's equation supposedly captures the slope of that long term trend line.

The story however does not end there. Rising prices signal to consumers (and producers) to adjust their activities by searching for relatively cheaper substitutes. Hence the search for renewable energy sources to replace oil, at least at the margin. The price signal - and consequent behavior adjustment - is precisely what averts a "collapse" in consumption as the resource is finally exhausted.

Unfortunately our baser instincts drive us to interfere with this economic process. Through our government, we want those greedy oil companies to profit less. We also accept interventions to impose "energy conservation", like banning this or that "frivolous" use of energy (Christmas lights, driving at the speed limit, etc.) This is a lot of wasted energy (pun intended). And taxing away those profits tells oil companies to shy away from risky ventures like oil exploration - precisely the set of activities needed to keep price growth in check. Ultimately some want the government to own all the oil companies - yeah, like that's gonna work.

I'm not saying that all intervention is bad. Market failures may justify some interventions, say in research and development, setting up infant renewable resource industries, imposing a tax on carbon emissions, and so on. But the distinction between bad and good intervention is subtle. Too often it vanishes in the scramble to appear to do something, anything, against $100 oil. Folks, let that $100 sign tell you what to do.

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