“Megan McArdle”:http://www.janegalt.net/blog/archives/004824.html responds to my previous post about third parties, suggesting that Barbara Ehrenreich (and I) have “about as tenuous a connection to reality as the folks who brought us Pepsi Clear.” Her counter-argument:
* That ‘first-past-the-post’ voting tends to produce two party systems.
* That presidential systems are much more prone to two-partyism than parliamentary ones.
* That the reason why Ehrenreich’s (or indeed McArdle’s ideas) don’t become policy isn’t because they’re blocked by the system, but because most Americans disagree with them.
* Therefore: third-partyism is an exercise in futility.
These arguments are exactly the sort of thing that we political scientists like to claim that we know something about (I note in passing that Megan’s confident assertion of these empirical relationships sits somewhat awkwardly with her belief that political science “doesn’t have much to do with falsifiable predictions”:http://www.janegalt.net/blog/archives/004125.html). On the first of these claims, there’s evidence from the literature to suggest that McArdle is sort of right (but not in a way that really helps her overall argument). On the second, there’s evidence to suggest that she’s fundamentally wrong. On the third, she seems to be on thin ice (if she’s making a limited claim) or falling through into the river beneath (if she’s making a strong general argument).