A Remark on CFT Realization of Quantum Doubles of Subfactors. Case Index < 4

It is well-known that the quantum double $D(N\subset M)$ of a finite depth subfactor $N\subset M$, or equivalently the Drinfeld center of the even part fusion category, is a unitary modular tensor category. Thus should arise in conformal field theory. We show that for every subfactor $N\subset M$ with index $[M:N]<4$ the quantum double $D(N\subset M)$ is realized as the representation category of a completely rational conformal net. In particular, the quantum double of $E_6$ can be realized as a $\mathbb Z_2$-simple current extension of $\mathrm{SU}(2)_{10}\times \mathrm{Spin}(11)_1$ and thus is not exotic in any sense. As a byproduct we obtain a vertex operator algebra for every such subfactor. We obtain the result by showing that if a subfactor $N\subset M$ arises from $\alpha$-induction of completely rational nets $\mathcal A\subset \mathcal B$ and there is a net $\tilde{\mathcal A}$ with the opposite braiding, then the quantum $D(N\subset M)$ is realized by completely rational net. We construct completely rational nets with the opposite braiding of $\mathrm{SU}(2)_k$ and use the well-known fact that all subfactors with index $[M:N]<4$ arise by $\alpha$-induction from $\mathrm{SU}(2)_k$.Comment: 16 pages, 3 figures. Comments are welcome

Endowment effect theory and the Samuelson solution : a thought experiment

Thaler (1980) employs prospect theory to explain the endowment effect, i.e. the empirically observed disparity between the willingness to pay for a certain good (WTP) and the willingness to accept retribution payments in exchange for giving up this good (WTA). This disparity is caused either by the disutility from parting with one?s endowment and/or by an extra utility from ownership which is not anticipated by individuals who are not endowed with the good. These effects may not apply to public goods because consumers are not given exclusive property rights. The graphical tools introduced by Samuelson (1954) are applied to show how these effects influence the allocation of resources among private and public goods. An inefficient allocation only occurs if the ownership utility effect applies to one good but not to the other

Party competition in a heterogeneous electorate – the role of dominant-issue-voters

This paper provides a theoretical model of party competition in a heterogeneous electorate. The latter consists of numerous groups of dominant-issue-voters who base their voting decision primarily on one issue of the political agenda. Parties follow a lexicographic objective function, aiming to gain power at minimum programmatic concessions. The emerging pattern of movement in policy platforms is fundamentally different to the concept of convergence proposed by the spatial theory of voting. Rather than the centre of the scale of policy preference, its extreme ends, occupied by dominant-issue-voters, attract the policy platforms. The difference in policy platforms is not reduced. The conclusions are found to be compatible with some major empirical findings of the Manifesto Research Group. --voters,incomplete information,political parties,convergence

On the Turnaround of Vacancy Stocks: The Stock Flow Model for the German Residential Rental Market

We apply the stock flow model for the German residential rental market using a data set that includes the overwhelming majority of nomenclature of territorial units for statistics (NUTS) 3 regions for the 2004-2007 period. Aside from proving conditional rental price convergence, we have detected a turnaround in vacancy stocks between the short and the long term. While East German counties and West German independent cities currently exhibit the highest and lowest vacancy rates, respectively, the opposite holds true at equilibrium. Leaning on theoretical suggestions, landlords in well-developed areas have incentives to hold onto vacancies in view of future rent increases. Our results support this idea, which demonstrates the significantly positive impact of household income and net birth rate on the natural vacancy rate.Rental Market; Adjustment Process; Natural Vacancy Rate; Regional Analysis; Germany

Institutional choice in social dilemmas: An experimental approach

This paper presents an experimental study on the ability of human groups to escape the tragedy of the commons through institutional change. It shows that the groups identify institutional change as a means of resolving social dilemmas and are ready to apply it even if the change requires an unanimous vote. At the same time, the groups who were given the right to change the rules performed poorer on average than the control-groups. This result stands in contradiction to elementary economic reasoning as well as the results of previous experimental studies. --social dilemmas,common pool resource,laboratory experiment,group behavior,institutional choice

Determinants of the influence of voters and interest groups on the political decision making process

This paper provides a comprehensive theoretical model of the political decision making process. Therein two ideologically different political parties compete for power. Their primary instrument in this competition are programmatic concessions in favor of voters and interest groups. As any concession causes losses in utility for the party members, the parties try to win the election with as little concessions as possible. The efficient amount of concessions and their distribution on different groups of voters and interest groups is derived. These concessions are taken as an indicator for the influence of these two groups of political agents on the political decision making process. Hence the political model developed in this paper helps to determine the political influence of voters and interest groups. The illustrations show that the efficient amount of concessions depends on the closeness of the election race. The closer the initial distribution of votes, the more concessions can voters and interest groups wring from the political parties. The characteristics of the political landscape, e.g. the share of informed voters and the degree of ideological polarization, are found to determine the efficient amount of concessions and thus the influence of voters and interest groups on the political decision making process. --Public Choice,theory,voters,interest groups,election