[EM] Rob Richie's criticism of Approval Voting

[Jonathan Lundell]

At 2:18 PM -0600 6/13/06, Jan Kok wrote:
>One bit of help I could use: Is anyone familiar with the article Rob
>mentions in this paragraph?
>
>>  Jack Nagel, a UPenn professor, has an important new article out 
>>this year called "Burr's Dilemma" that goes into how this flaw 
>>played out in the 1796 and 1800 presidential election, where the 
>>presidential electors (who at that time had two equally weighted 
>>votes), made strategic mistakes with major consequences in both 
>>elections. Nagel used to say approval voting was better, but now 
>>says IRV is better.

The key slide from Nagel's presentation:

Statement of the Burr Dilemma

When three or more candidates compete for an office that only one can 
win, and voters (V) may support two (or more) of them by casting 
equal (approval) votes, candidates (C1 and C2) seeking support from 
the same group (G) of voters will maximize their respective votes if 
all members of G vote for both C1 and C2.   Both candidates thus have 
an incentive to appeal for shared support.  However, if such appeals 
succeed completely and neither candidate receives votes from members 
of V-G, the outcome will be at best a tie in which neither C1 nor C2 
is assured of victory.  Each candidate therefore has an incentive to 
encourage some members of G to vote only for himself or herself.  If 
both C1 and C2 successfully follow such a strategy, either or both 
may receive fewer votes than some other candidate C3 supported by 
members of V-G.  The risk that both C1  and C2  will lose is 
exacerbated if a retaliatory spiral increases the number of single 
votes cast by members of G.  At the limit, such retribution reduces 
approval voting to conventional single-vote balloting among the 
members of G or, if the problem is endemic, among all voters.  The 
nearer that limit is approached, the lower the probability that 
advantages claimed for approval voting will be realized..

-- 
/Jonathan Lundell.