As promised, Volokh guest blogger David Schleicher posted his preferred explanation for the persistence of one-party urban democracy.  As first glance, his story seems pretty different from mine.  Here’s his lead-in: “I argue that the lack of competition in city council elections can only
be explained by understanding the laws governing local elections and
how they interact with voter behavior.”

At least on my reading, though, election laws play no fundamental role in Schleicher’s story; it’s his assumptions about “voter behavior” assumptions that matter.  And I’m pleased to report that Scheicher and I turn out to be roughly on the same page.  He explains:

[T]he vote in local elections will directly track the vote in national
elections. Voters with little information will use the information that
the law provides to them – the party name on the ballot. If
“Republican” and “Democrat” provide a non-zero amount of information
about a candidate, a voter with no other information (by assumption)
about the candidate will rationally use the national party heuristic to

The question is why the minority local party doesn’t modify its
issue stances to become popular at the local level. By assumption, the
only way it could do this is if it did so on a city-wide level –
individual candidates can’t get enough attention…

Schleicher closes with a great anecdote:

The dramatic effect of the lack of information on local city council
elections can be seen if one considers the case of New York City’s
Councilmanic District Five on the Upper East Side of Manhattan. In the
2001 local election, Gifford Miller, a powerful and well-known
Democratic incumbent who directly after the election would become
Speaker of the City Council, faced a relatively unknown candidate named
Robert Strougo. Not surprisingly, Miller won 68 percent of the vote to
Strougo’s 31 percent, neatly tracking the 2-1 dominance of Democrats in
the district.

In 2005, a perfect storm of factors lined up to reverse this result.
First, Miller could not run for reelection because of term limits. His
aide, Jessica Lappin, who had never run for public office before, was
the Democratic candidate. Second, Republican Mayor Michael Bloomberg
reached new heights of popularity, particularly on the Upper East Side
(he would end up winning 59 percent of the citywide vote and more than
80 percent of the vote on the Upper East Side). In District Five, the
Republicans nominated Joel Zinberg, a former Democrat, cancer surgeon
and Yale-educated lawyer, who built his candidacy around Bloomberg’s
popularity, declaring his goal as furthering the Mayor’s agenda. The
New York Times and the New York Post endorsed Zinberg, as did
Bloomberg. In the face of this, Lappin’s campaign simply sounded a
single theme. When asked by a local paper what differentiated the
candidates, she responded, “I’m a Democrat. I mean, that’s sort of the
most obvious difference between us… He’s a Republican, and I’m proud
to be a Democrat, and I think that certainly distinguishes us.”

The result of the election was a near carbon copy of the 2001 race:
Lappin received 65 percent of the vote to Zinberg’s 35 percent.

My only quibble is that my “party preference” mechanism seems to fit the facts better than Schleicher’s “lack of information” story.  He could naturally reply that “party preference” is based on “lack of information,” but I’m not so sure.  Why can’t we just look upon New York Democrats as the political equivalent of the New York Yankees?