Notes on “substitutions”

Alex Tabarrok

The misunderstanding came from thinking that we need every user of fuel to find substitutes. Not at all! In reality, as fuel prices rise, those with the lowest substitution costs will switch first, freeing up fuel for users who have more difficulty finding alternatives. Just one industry with favorable substitution possibilities, combined with a few moderately adaptable industries, can produce a significant overall effect. Moreover, there are nearly always some industries with viable substitution options. To see why reverse the usual story and ask, if fuel prices fell by 50% could your industry use more fuel? And if fuel prices fell by 50% are their industries that could switch into the now cheaper fuel?

People often find it easier to imagine new uses rather than ways to reduce existing consumption. However, it is typically the new uses that are scaled back first. Tyler and I illustrate this with our jet and rubber ducky graph. Although jet aircraft won’t shift away from oil even at high prices, rubber (actually plastic) duckies, which are made from oil, can find substitutes–wood, for example–when oil prices rise. And if plastic ducky manufacturers cannot find substitutes, they go out of business, freeing up more oil for other uses. In this way, the market identifies the least valuable goods to cease production, another kind of substitution.