Tideman: Collective Decisions and Voting
I recently started reading through Nicolaus Tideman's book "Collective Decisions and Voting," and so far it's very interesting. I wanted to recommend it and open up a thread for discussion of some of the concepts he addresses. I think his definitions of decisions, collectivities, and of collective decisions are good.
So far he has classified modes of collective decision-making according to the absence or presence of dissatisfaction, exchange, and effort. This divides the modes into several categories. He first addresses those in what he calls the "agreement-on-outcome" family:
- Consensus: Discovered and Achieved
- Pseudo-consensus: Immediate and Achieved
- Trade: Purchase and Negotiated exchange
- Extortion: Hold-up and Treaty
and then those in the "agreement-on-procedure" family:
- Random Process
I like his taxonomy of meta criteria he suggests for general collective decision procedures, which include
- Efficiency: Outcome and Procedural
- Equity: Symbolic, Material, and Productivity-based Inequality
- Stability: Restoration, and Preservation
Here are various excerpts from Tideman about voting, which I tend to agree with:
"The primary claim of voting to outcome efficiency rests on a conception of symmetry of interests. If the average intensity of interest of those in the majority is the same as for those in the minority, then outcome efficiency lies with following the wishes of the majority. However, because the average intensity of interests of the majority and the minority are not always equal, voting does not achieve perfect outcome efficiency."
"...when voting is used, a majority coalition is able to obtain disproportionate benefits for itself at the expense of those outside the coalition, reducing material equality... coalitions do not all have the same chance of forming."
"Voting tends to be not very good in terms of preservation, because it permits a majority to impose its will on the minority. The damage that voting does to preservation is limited to some extent by constitutions, and also by the tendency for logrolling and other forms of vote trading to emerge..."
"The regular existence of disappointed minorities gives voting a poor rating in terms of preservation."
"Voting... is particularly attractive when the members of the collectivity are seen as having the same underlying interests, but as having different perceptions of how those interests are best served."
I think the three meta-criteria are very sensible and he appears to be trying to address majoritarianism at the same time. I know that the method Ranked Pairs that he invented is a very reasonable and robust Smith (and hence Condorcet) compliant system, and lately I have been persuaded to lean into the Condorcet camp. I wonder if any of you have read this book before and/or if you have any thoughts about what you read.
I am presently reading through his analysis on voting systems, which has gotten less philosophical and more mathematical, including a probabilistic analysis based on data and a model he develops on the existence of “cyclic anomalies” such as Condorcet cycles. I wonder how or if he will be able to address and/or analyze majoritarianism in a reasonable way. He seems to focus predominantly on rank-order systems, which is reasonable enough to me.
In any case I also find this discussion interesting: