Q: How Are the Swing-State Economies Doing? A: Who Cares?

The swing states are swinging toward Obama, Chris Cillizza writes. Among the dozen in-play states, most have unemployment rates below the national average of 8.2 percent. In four more, joblessness is dropping quickly. Good news for the president?

Maybe. But when it comes to the messy relationship between economics and elections, it's hard to see how important state statistics really are.

It is true enough that there is no such meaningful thing as a "national economy." It makes more sense to say there exists a network of city and state economies whose various strengths and weaknesses are glossed over by focusing on 50-state aggregate numbers. At the same time, the political science suggests that we vote based on national trends.

Research by John Sides and Thomas Holbrook found that state-level economies had precisely zilch to do with presidential election outcomes between 1960 and 1984. Further studies through the 1980s and 1990s (via Sides) also found that the national economy outweighed the effect of state and county numbers. A 1% increase in the national unemployment rate is associated with about a 3 percentage point decrease in presidential approval, according to one paper by Stephen Ansolabehere, Marc Meredith, and Erik Snowberg. The correlation between state-level unemployment and approval is only 20% as strong.

All politics is local, but it's the national fundamentals that seem to matter most. Why? Here are two theories.

The first theory is that voters are reasonable. They understand that presidents are not omnipotent, that their powers do not extend into every corner of the economy, that they cannot be blamed for local trends like overconstruction in the suburbs, or infrastructure spending delays, or bids for factories that fall through because some other metro offered a better tax credit for the multinational corporation. So they're more likely to focus on national trends that they feel the president can control. (Sounds reasonable, but if the president can't control any individual metro economy, why does it make more sense to think they deserve credit and blame for the aggregated outcome of ALL metro economies?)

The second theory is about how we form opinions. I don't know many undecided voters myself, but I doubt that many of these families are printing out economic, social and foreign policy platforms, methodically moving through the competing documents, point for point, calling think tank experts and consulting constitutional lawyers to make sense of which candidate would better protect civil liberties, provide the conditions for economic growth, and so forth. Rather, we look for stories that strike a chord with our values. Rather than leave yourself undecided about every single metric, it's considerably easier to make up your mind about a small number of things -- taxes should be lower; abortions should be prevented; foreign policy rhetoric should be more aggressive -- and pay attention to the stories built around them. The vast majority of the narratives that drive national elections aren't local. They're national. They're built and executed and told and retold by national media organizations focusing on national trends.

In short, if undecided voters are swayed by the most available and most often-repeated stories about the candidates and the country, it's considerably more likely that they will be swayed by the stories they see on national media. As a result, even as we're aware of local economy's health, voters are less likely to associate it with Washington.