Arrow's impossibility theorem is a key result in social choice theory, showing that no ranking-based decision rule can satisfy the requirements of rational choice theory. [1]

2014年10月13日 · Kenneth Arrow’s “impossibility” theorem—or “general possibility” theorem, as he called it—answers a very basic question in the theory of collective decision-making. Say there are some alternatives to choose among.

2024年8月7日 · Arrow's impossibility theorem is a social-choice paradox illustrating the flaws of ranked voting systems. It states that a clear order of preferences cannot be determined while adhering to...

2023年10月19日 · Arrow’s impossibility theorem states that it is impossible to have a voting system that delivers fair and sensible results on a consistent basis. Every vote counts. That phrase is one of the founding pillars of a democracy .

impossibility theorem, in political science, the thesis that it is generally impossible to assess the common good. It was first formulated in Social Choice and Individual Values (1951) by Kenneth J. Arrow, who was awarded (with Sir John R. Hicks) the Nobel Prize for Economics

2013年12月18日 · Theorem (Condorcet’s jury theorem): For each state of the world \(x \in \{-1,1\}\), the probability of a correct majority decision, \(Pr(V = x | X = x)\), is greater than each individual’s probability of a correct vote, \(Pr(V_i = x | X = x)\), and converges to 1, as the number of individuals \(n\) increases.

Now, by its very name, the impossibility theorem engenders a certain degree of pessimism: if something is “impossible,” it’s pretty hard to accomplish. As applied to voting, the theorem appears to

In the language of decisiveness, Arrow’s theorem says that there is a decisive coalition that has only one member. A fundamental question is whether there are any decisive coalitions. The answer is yes. Indeed, the Pareto Principle may be restated as follows. , is decisive.

Arrow’s Impossibility Theorem is one of the first impossibility proofs covered in this course. Before stating it, we will introduce two prerequisite voting desiderata. b by the social welfare function (SWF) and be cannot be the output of the social choice function (SCF).

Arrow’s Impossibility Theorem states that a ranked-voting electoral system cannot reach a community-wide ranked preference by converting individuals’ preferences while meeting all the conditions of a fair voting system.