Ordinal notions of submodularity

We consider several ordinal formulations of submodularity, defined for arbitrary binary relations on lattices. Two of these formulations are essentially due to Kreps [Kreps, D.M., 1979. A representation theorem for “Preference for Flexibility”. Econometrica 47 (3), 565–578] and one is a weakening of a notion due to Milgrom and Shannon [Milgrom, P., Shannon, C., 1994. Monotone comparative statics. Econometrica 62 (1), 157–180]. We show that any reflexive binary relation satisfying either of Kreps’s definitions also satisfies Milgrom and Shannon’s definition, and that any transitive and monotonic binary relation satisfying the Milgrom and Shannon’s condition satisfies both of Kreps’s conditions.     

The geometry of revealed preference

In this paper, we examine how the geometry underlying revealed preference determines the set of preferences that can be revealed by choices. Specifically, given an arbitrary binary relation defined on a finite set, we ask if and when there exists a data set which can generate the given relation through revealed preference. We show that the dimension of the consumption space affects the set of revealed preference relations. If the consumption space has more goods than observations, any revealed preference relation can arise. Conversely, if the consumption space has low dimension relative to the number of observations, then there exist both rational and irrational preference relations that can never be revealed by choices.     

Condorcet efficiency of positional voting rules with single-peaked preferences

Consider a three-alternative election with n voters and assume that preferences are single-peaked. LetC(λ,n) be the Condorcet efficiency of the rule that assigns 1,λ and 0 points (respectively) to each first, second and third place vote. An exact representation is obtained forC(λ,∞). This relation shows that Borda rule (λ=1/2) is not the most efficient rule. In addition to this result, exact closed form relations are provided forC(0,n),C(1/2,n) andC(1,n). All these relations are obtained by assuming that every admissible configuration of preferences is equally likely to occur. This research was supported in part by the Swedish Insitute     

Political parties' use of web based marketing: some preliminary findings relating to first‐time voters in the 2005 general election

• This paper examines the marketing of political parties, via websites, in the 2005 UK general election with specific reference to first‐time voters (age 18–24). Common perception views young voters as predominantly politically apathetic and less likely to vote than older generations. However, research literature suggests given the right message and medium, the group will engage in the political process. Could the Internet provide a path to engaging younger voters and will websites become a key marketing vehicle for political parties?
• Young voters were asked to review political party websites using an extended web assessment method (EWAM), which is an evaluation tool created to determine both the importance and presence of website evaluation criteria. Preliminary research suggests that respondents felt the Internet had a significant role to play in the election process and marketing of campaign messages. However, while political parties scored well in relation to the technical/software aspects of website design, participants felt website material had little appeal and were ineffective in influencing voter intent.

Copyright © 2006 John Wiley & Sons, Ltd.     

Identity, reputation and social interaction with an application to sequential voting

We analyze binary choices in a random utility model assuming that agent’s preferences are affected by conformism (with respect to the behavior of the society) and coherence (with respect to identity). We show that multiple stationary equilibria may arise and that the outcome looks very different from a society where all the agents take their decisions in isolation. We quantify the fraction of agents that behave coherently. We apply the analysis to sequential voting when voters “like to win”. Compared to the present literature, we enrich the setting assuming that each voter is endowed with an ideology and we consider the interplay between coherence and the desire to vote with the (perceived) majority.     

Intergenerational conflict and the political economy of higher education funding

We examine how a population's age distribution and a growing divide between the ethnic composition of older and young generations is likely to affect support for higher education funding. Using detailed survey data on voter preferences for higher education funding and precinct-level vote returns from locally-funded community college bond referenda in California, we find that older voters are significantly less supportive of higher education funding than younger voters and that support among older non-Hispanic white voters is particularly weak when those voters reside in a jurisdiction where the college-age population is more heavily Hispanic.     

网络对社会关系的异化

网络为社会关系的发展提供了一个全新的虚拟空间。今天,网络已成为社会关系发展的重要领域,但同时也带来人际关系、群际关系、代际关系的异化。文章就网络对社会关系各个方面的异化分别进行讨论。     

网络对社会关系的异化

网络为社会关系的发展提供了一个全新的虚拟空间。今天,网络已成为社会关系发展的重要领域,但同时也带来人际关系、群际关系、代际关系的异化。文章就网络对社会关系各个方面的异化分别进行讨论。     

A methodology for testing a new spatial model of elections

The purpose of this paper is to offer a methodology for testing a new spatial theory of elections. Specifically, it is shown that the new spatial model of elections developed by Enelow and Hinich (1984a) is statistically equivalent to assuming that a classical factor structure underlies the data that voters provide concerning the issue positions of themselves and the candidates. A factor analysis of the sample correlation matrix of candidate variables averaged over voters and issues provides consistent estimates of the candidate locations in the space of predictive dimensions postulated by Enelow and Hinich, and the facor scores assigned to the voters can be used to project the voters onto the same predictive space with the candidates. This new scaling method is used to locate the positions of voters and candidates in the underlying predictive space of the 1980 Presidential election. Internal checks confirm the empirical adequacy of the candidate locations, and probit analysis is used as an external check on the empirical adequacy of the voter locations. For the pre-election data, no loss of accuracy in predicting voter choice was found in moving from the issue data to the estimated factor locations of voters and candidates. For the post-election data, a modest drop in accuracy was discovered. Overall, the empirical adequacy of factor analysis was confirmed as a methodology for testing the new Enelow-Hinich spatial model of elections.     

Endogenous party structure

This paper proposes a model of two-party representative democracy on a single-dimensional political space, in which voters choose their parties in order to influence the parties’ choices of representative. After two candidates are selected as the median of each party’s support group, Nature determines the candidates’ relative likability (valence). Based on the candidates’ political positions and relative likability, voters vote for the preferable candidate without being tied to their party’s choice. We show that (1) there exists a nontrivial equilibrium under natural conditions, and (2) the equilibrium party border and the ex ante probabilities of the two-party candidates winning are sensitive to the distribution of voters. In particular, we show that if a party has a more concentrated subgroup, then the party tends to alienate its centrally located voters, and the party’s probability of winning the final election is reduced. Even if voter distribution is symmetric, an extremist party (from either side) can emerge as voters become more politically divided.     

p2: a random effects model with covariates for directed graphs

A random effects model is proposed for the analysis of binary dyadic data that represent a social network or directed graph, using nodal and/or dyadic attributes as covariates. The network structure is reflected by modeling the dependence between the relations to and from the same actor or node. Parameter estimates are proposed that are based on an iterated generalized least-squares procedure. An application is presented to a data set on friendship relations between American lawyers.     

Epistemic democracy with correlated voters

We develop a general theory of epistemic democracy in large societies, which subsumes the classical Condorcet Jury Theorem, the Wisdom of Crowds, and other similar results. We show that a suitably chosen voting rule will converge to the correct answer in the large-population limit, even if there is significant correlation amongst voters, as long as the average covariance between voters becomes small as the population becomes large. Finally, we show that these hypotheses are consistent with models where voters are correlated via a social network, or through the DeGroot model of deliberation.     

Voter turnout in a multidimensional policy space

Many factors influence the likelihood of citizens turning out to vote. In this paper we focus our attention on issue voting, that is, on the likelihood that different policies offered by politicians affect the probability of voting. If voters consider both the benefits and the costs of voting, rational voters will only vote when politicians offer differentiated policies. In a multidimensional policy space this implies that citizens only vote when they perceive enough difference on the issues they care about the most. We investigate the role of voter abstention due to indifference in a unidimensional and a multidimensional policy setting using data from the US National Election Studies for 1972–2000 and find support for our predictions: voters perceiving a small difference between the platforms of the Democratic and Republican parties are less likely to vote; and voters who perceive the two parties as more different on a larger number of issues are significantly more likely to vote.     

Non-anonymous ballot aggregation: An axiomatic generalization of Approval Voting

We study axiomatically situations in which the society agrees to treat voters with different characteristics distinctly. In this setting, we propose a set of intuitive axioms and show that they jointly characterize a new class of voting procedures, called Type-weighted Approval Voting. According to this family, each voter has a strictly positive and finite weight (the weight is necessarily the same for all voters with the same characteristics) and the alternative with the highest number of weighted votes is elected. The implemented voting procedure reduces to Approval Voting in case all voters are identical or the procedure assigns the same weight to all types. Using this idea, we also obtain a new characterization of Approval Voting.     

Tiebout Revisited: Redrawing Jurisdictional Boundaries

Central city households who subsidize local public sector goods through local property taxes have an incentive to flee from the city or to change the jurisdiction's boundary. We focus on the latter case, a neighborhood's attempt to deannex from a central city and subsequently annex to a suburb. The difficult theoretical problem is to explain why a large percentage of central city voters supported the deannexation proposal, most apparently becoming worse off if the issue was approved. While no explanation is consistent with fully rational voters, it appears that high property value owning voters supported the attempt in hope of being part of the next wave of deannexers.     

Impossibilities for strategy-proof committee selection mechanisms with vetoers

When a group of voters selects a committee out of a set of candidates, it is common and often desirable to endow these voters with some veto power. I present impossibility results showing that even limited veto power makes many mechanisms of interest manipulable. This applies in particular (i) to mechanisms the range of which contains a degenerate lottery in which a committee is chosen for sure and (ii) to mechanisms that are constructed from extensive game forms with a finite number of strategies. These impossibilities hold on a large set of domains including the domain of additive preferences, and even when probabilistic mechanisms are allowed and voters can report cardinal preferences.     

On the extension of binary relations in economic and game theories

Decisions in Economics and Finance - Szpilrajn’s extension theorem on binary relations and its strengthening by Dushnik and Miller are fundamental in economic and game theories....     

Binary effectivity rules

A social choice rule (SCR) is a collection of social choice correspondences, one for each agenda. An effectivity rule is a collection of effectivity functions, one for each agenda. We prove that every monotonic and superadditive effectivity rule is the effectivity rule of some SCR. A SCR is binary if it is rationalized by an acyclic binary relation. The foregoing result motivates our definition of a binary effectivity rule as the effectivity rule of some binary SCR. A binary SCR is regular if it satisfies unanimity, monotonicity, and independence of infeasible alternatives. A binary effectivity rule is regular if it is the effectivity rule of some regular binary SCR. We characterize completely the family of regular binary effectivity rules. Quite surprisingly, intrinsically defined von Neumann–Morgenstern solutions play an important role in this characterization.     

Characterization of the existence of semicontinuous weak utilities

In this paper we characterize the existence of semicontinous weak utilities for acyclic binary relations. We shall reobtain directly from that result sufficient conditions that are available in the literature.     

Targeted political advertising and strategic behavior by uninformed voters

We consider the case where political advertising is targeted to a subset of uninformed voters and show how pressure groups, candidates, and uninformed voters interact to achieve an equilibrium outcome. The paper accomplishes the following: (1) It derives the optimal behavior of those uninformed voters who do not received targeted campaign advertising. (2) It suggests that previous results may have exaggerated the power of pressure groups and political advertising—even when there is directed advertising, any negative effect is mitigated by strategic behavior of the uninformed. (3) In the limit, pressure group donations move the outcome toward the median voter, contrary to what much of the literature on pressure groups claims.