https://graphics.stltoday.com/apps/elections/st-louis-city/ (Proposition D)
I think CES was involved with this to some degree, so congrats to them and the STL Approves campaign on the W.
* Technically it’s not “pure approval” since there is a runoff between the top two approval getters, but the principles that make Approval desirable still apply.
I reckon it depends on the level of information. Given perfect information (and rational voters), it’s impossible that there is a Condorcet winner other than the approval winner. So how do we decide the best candidate in the absence of a Condorcet winner? Certainly not the runoff, as all that tells you is which candidate has the direct beat-path and which has the indirect beat-path. Maybe the approval election we just held (i.e. the runoff is pointless)?
Granted, the likelihood that a second-most-approved runoff winner is a Condorcet winner increases as the level of information diminishes, but the burden of proof is on the proposers of the more complex system to demonstrate that that likelihood is sufficiently high to justify defeating the approval winner.
I don’t necessarily believe that the runoff step is the most useful thing in the world. Reading their explanation, I suspect it was included for rhetorical purposes; people are more familiar with a top 2 runoff since it is far more widespread than Approval. I have seen quite a few people who dismiss electoral reform when legislation comes up by saying “just hold a runoff, that’s the proper way.” When I say that the STL system has many of the same advantages as pure approval, I mean it won’t be more likely to make the kinds of misreads that FPTP and IRV do.