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“Rationality” reinforces, does not compete with, other models of behavior

John Sides followed up on a discussion of his earlier claim that political independents vote for president in a reasonable way based on economic performance. John’s original post led to the amazing claim by New Republic writer Jonathan Chait that John wouldn’t “even want to be friends with anybody who” voted in this manner.

I’ve been sensitive to discussions of rationality and voting ever since Aaron Edlin, Noah Kaplan, and I wrote our article on voting as a rational choice: why and how people vote to improve the well-being of others.

Models of rationality are controversial In politics, just as they are in other fields ranging from economics to criminology. On one side you have people trying to argue that all behavior is rational, from lottery playing to drug addiction to engaging in email with exiled Nigerian royalty. Probably the only behavior that nobody has yet to claim is rational is blogging, but I bet that’s coming too. From the other direction, lots of people point to strong evidence of subject matter ignorance in all fields ranging from demography to the Federal budget to demonstrate that, even if voters think they’re being rational, they can’t be making reasoned decisions in any clear senses.

Here’s what I want to add. In the usual debates, people argue about whether a behavior is rational or not. Or, at a more sophisticated level, people might dispute how rational or irrational a given action is. But I don’t think this is the right way of thinking about it.

People have many overlapping reasons for anything they do. For a behavior to be “rational” does not mean that a person does it as the result of a reasoned argument but rather that some aspects of that behavior could be modeled as such. This comes up in section 5.2 of my article with Edlin and Kaplan: To model a behavior as rational does not compete with more traditional psychological explanations; it reinforces them.

For example, voter turnout is higher in elections that are anticipated to be close. This has a rational explanation—if an election is close, it’s more likely that you will cast the deciding vote–and also a process explanation: if an election is close, candidates will campaign harder, more people will talk about the election, and a voter is more likely to want to be part of the big stories. These two explanations work together, they don’t compete: it’s rational for you to vote, and it’s also rational for the campaigns to try to get you to vote, to make the race more interesting to increase your motivation level.

I don’t anticipate that this note will resolve some of the debates about participation of independents in politics but I hope that this clarifies some of the concerns about the “rationality” label.

P.S. John is better at engaging journalists than I am. When Chait wrote something that I didn’t like and then responded to my response, I grabbed on a key point in his response and emphasized our agreement, thus ending the debate (such as it was), rather than emphasizing our remaining points of disagreement. John is better at keeping the discussion alive.


  1. bsirolly says:

    Sounds like Sibley in "The Rational versus the Reasonable." The idea is summed up by Gerwith in an abstract as, "[R]ationality consists in means-end calculation of the most efficient means to one’s ends (which are usually taken to be self-interested), while reasonableness consists in equitableness whereby one respects the rights of other persons as well as oneself."

  2. Ole Rogeberg says:

    Hi Andrew,

    I tried to understand this, but found it puzzling – especially the claim that rational choice reinforces psychological explanations.

    If there's a number of influencing factors at work, and one of them actually is a rational means-end deliberation, then I suppose you could say that including this "rational" factor will allow you to explain more of the variance in the outcome. Is that what you mean by "supplementing the other factors"?

    As for your example – here the "psychological" and "rational" factors pull the same way and are "triggered" by the same thing (a close election). In that sense, they "reinforce" each other in this case, but I can't see any reason why the two effects should tend to have the same sign in general.

    In economics, my experience is that those who argue in favor of modelling things as rational in practice end up arguing that *every* systematic aspect of the behavior in question should be rational. They don't tend to think that it should be one of many elements in a mix. (It may therefore just be my economics background that confuses me.)

  3. Vic says:

    Thanks so much for this post!

    I have to echo Ole's comments — I have an economics background as well and in my experience economists tend to not be very inquisitive about the notion of rationality they appeal to (if anything these seem to bristle at any questioning of their assumptions).

    In any case, it's long seemed to me that though most decisions most of the time are made irrationally (in the sense that they're made on the basis of intuition or habit and not of utility maximization), most decisions can also be seen /as if/ they are rational (ie. modeled as such), since in general I suspect people intuitively end up trying to maximize their expected utility based on their available knowledge anyway.

    I'm curious if you have any thoughts on behavioral economics — do you think Ariely, Sunstein, et al, operate with the same modeler's definition of rationality/irrationality as you're describing here?