The separability problem is a concept from the field of

social choice theory Social choice theory is a branch of welfare economics that extends the Decision theory, theory of rational choice to collective decision-making. Social choice studies the behavior of different mathematical procedures (social welfare function, soc ...

that describes the situation where two or more issues up for vote on a

ballot A ballot is a device used to cast votes in an election and may be found as a piece of paper or a small ball used in voting. It was originally a small ball (see blackballing) used to record decisions made by voters in Italy around the 16th cent ...

either are, or are perceived as, related. The separability problem commonly manifests itself most intensely in

referendum A referendum, plebiscite, or ballot measure is a Direct democracy, direct vote by the Constituency, electorate (rather than their Representative democracy, representatives) on a proposal, law, or political issue. A referendum may be either bin ...

s and in voting on multiple charges before

juries A jury is a sworn body of people (jurors) convened to hear evidence, make findings of fact, and render an impartial verdict officially submitted to them by a court, or to set a penalty or judgment. Most trial juries are " petit juries", an ...

or panels of

judge A judge is a person who wiktionary:preside, presides over court proceedings, either alone or as a part of a judicial panel. In an adversarial system, the judge hears all the witnesses and any other Evidence (law), evidence presented by the barris ...

s, where simultaneous

voting Voting is the process of choosing officials or policies by casting a ballot, a document used by people to formally express their preferences. Republics and representative democracies are governments where the population chooses representative ...

is employed. Some or all voters view the approval or disapproval of one issue dependent on the approval or disapproval of another. The voters have no information on the outcome of related issues, so they simply cast their first preference votes. The outcomes of these decision-making

poll Poll, polled, or polling may refer to: Forms of voting and counting * Poll, a formal election ** Election verification exit poll, a survey taken to verify election counts ** Polling, voting to make decisions or determine opinions ** Polling pla ...

s are often displeasing to a majority of voters merely because simultaneous voting denied them the information on outcomes of individual issues or the opportunity to express preferences of outcomes of related issues. The solution to the separability problem for referendums would be set-wise voting, where the voter can express preferences for outcomes of related issues, as this process needs to be done at a particular time. For matters before juries or judicial panels, either set-wise or sequential voting can be employed to mitigate this problem, as all votes need not be cast in one instance. If sequential voting were employed, the outcome of every vote tally on an issue would be announced before a vote on the next issue would be taken. The drawback to sequential voting in this case would be that there is no means to guarantee that a juror would actually change a successive vote based on a prior verdict.

External links

Voting on Referenda:The Separability Problem and Possible Solutions
Article by Steven J. Brams, D. Marc Kilgour, and William Zwicker.
A problem with referendums
Article by Dean Lacy and Emerson Niou.
The Paradox of Multiple Elections
Article by Steven J. Brams, D. Marc Kilgour, and William Zwicker.
The Probability of Inconsistencies in Complex Collective Decisions
Article by

Christian List Christian List (born 1973) is a German philosopher and political scientist who serves as professor of philosophy and decision theory at the Ludwig Maximilian University of Munich and co-director of the Munich Center for Mathematical Philosop ...

. {{DEFAULTSORT:Separability Problem Public choice theory