Recent days have seen a number of articles like this one from the New York Times, in which it is claimed that people are changing their commuting patterns because of the high price of gas. The equation is pretty simple: higher gas prices = more expensive to drive to and from work = more use of mass transit. Although the article also cites increased urban congestion and the availability of wireless connections (and hence to ability to do online work while traveling) on mass transit trains as reasons for this change in commuter behavior, the main logic claimed involves cost-benefit calculations revolving around the price of gasoline.

I’m skeptical of this argument — and not just because of my knee-jerk opposition to rationalist models of individual decision-making. (Although admittedly that opposition does play a role here; I do think that there’s something quite immoral about reducing human social action to a set of instrumental choices based on calculations about expected values, but that’s another argument for another time and place.) In this case, I have two problems with the argument as presented. I don’t think that there’s a problem with the claim that “higher gas prices cause mass transit ridership numbers to go up”; I think there’s a problem with the purported causal mechanism driving that association. I don’t think that the rational calculation actually or unambiguously supports a greater use of mass transit, and I don’t think that people determine their commutes based on such calculations.

Take the calculation itself. If I am driving to work, the commute cost is not just the price of gas and tolls and parking, and not just the wear and tear on my car and whatever estimate of the cost of the stress associated with driving in traffic I can come up with (and this is a not inconsiderable technical measurement problem — how do you quantify the cost of stress? Estimated average medical bills? Surveys of peoples’ attitudes? Self-reported feelings of frustration? Incidents of road rage?). The cost of driving is also the earnings foregone by driving instead of working, or the utility sacrificed by driving instead of sleeping in or staying home or watching a morning episode of Star Trek or whatever. And then there’s the fact that in most cases taking mass transit adds to the commute time . . . sum all of that up and, well, the balance of costs and benefits is at the very least ambiguous. It is far from clear that taking the train to and from work actually does save you money. T fact that here in DC it costs me about $8/day between the commuter bus and the Metro to get to and from work, plus the effective doubling of my commute-time when I take the train, makes this a far from straightforward slam-dunk connection between the higher price of gas and a more affordable mass transit commute.

So I’m skeptical that the cost-benefit calculus actually points towards a greater use of mass transit. That said, mass transit numbers are up, and I think that does have to do with the higher price of gas; I just think that the mechanism is different. I think that the superior causal story here involves two factors: conservation consciousness, and emulation. “Conservation consciousness” catches up all of the recent popular concerns with natural resource depletion, global warming, ecological awareness, and a growing sense that unusual weather patterns are the result of aggregate human action; these themes have been a lot more prominent lately, as have the number of arguments linking these cultural commonplaces with particular courses of action like buying eco-friendly (if we ignore the mercury content of these items) lightbulbs. “Take the train instead of driving” extends the general “think globally, act locally” theme of the modern environmental movement in advanced industrialized societies, so it’s not surprising to see such claims in mass circulation. What do these claims do? I don’t think that they persuade people as much as they legitimate a course of action, render it a socially acceptable thing to do. Combine that kind of legitimation with the interrelated provision of infrastructural capacity to support such a course of action (i.e., the actual presence of a commuter rail system, which is “interrelated” with the legitimation strategy because the provision of the infrastructure is generally tied to the legitimation strategy itself — we have a commuter rail system because it was rendered a publicly acceptable course of action, possibly in similar eco-friendly terms) and you have a channel along which social action can easily flow.

But legitimation is only part of the story. Equally important, I’d posit, is the mechanism of emulation: someone who drives to work is complaining about the cost of gas, someone else who takes the train suggests that the driver ought to switch to mass transit, and uses her or his own example as a successful mass transit commuter as evidence that such a course of action is viable. The conversation, I think, isn’t about costs and benefits rationally calculated, even though the rhetoric of costs and benefits might be tossed around; vaguely reckoning with broad notions of “cost” and “benefit” is not, in my opinion, anything like an approximation to a rational cost-benefit calculation. Rather, it’s a conversation about acceptable courses of action, and it tells us a lot about our present-say culture that we feel the need to justify courses of action by referring to their “costs” and “benefits” even if we have no clear or defensible sense or estimate of what those costs and benefits are! What I think is going on in that hypothetical conversation is not a shared calculation, but a sharing of cultural commonplaces and examples — a sharing that just might make the mass transit option an acceptable and legitimate one.

That’s why I think that we are seeing increased mass transit ridership. When and if gasoline prices decline, it will be interesting to see how sticky the new commuting patterns are; if I’m right, they might survive a drop in prices for longer than a straight rationalist would expect.