The Borda rule,Condorcet consistency and Condorcet stability

Summary. The Borda rule is known to be the least vulnerable scoring rule to Condorcet inconsistency, Saari (2000). Such inconsistency occurs when the Condorcet winner (the alternative which is preferred to any other alternative by a simple majority) is not selected by the Borda rule. This note exposes the relationship between the Borda rule and the Condorcet q-majority principle as well as the Condorcet q-majority voting rule. The main result establishes that the Borda rule is Condorcet q-majority consistent when where k is the number of alternatives. The second result establishes that is the minimal degree of majority decisiveness corresponding to the Borda rule under sincere voting. The same majority is required to ensure decisiveness under the Borda rule and to ensure that a q-rule (the generalized q-majority Condorcet rule) is a voting rule. Received: April 8, 2002; revised version: July 17, 2002 Correspondence to:S. Nitzan     

On the topological social choice model

The main goal of this paper is to show that if a finite connected CW complex admits a continuous, symmetric, and unanimous choice function for some number n>1 of agents, then the choice space is contractible. On the other hand, if one removes the finiteness, we give a complete characterization of the possible spaces; in particular, noncontractible spaces are indeed possible. These results extend earlier well-known results of Chichilnisky and Heal.     

Strategic restraint in contests

Economic policy is modelled as the outcome of a (political) game between two interest groups. The possible ex-post (realized) outcomes in the game correspond to the proposed policies. In the literature policy proposals are exogenous. We extend such games by allowing the endogenous determination of the proposed policies. In a first stage the groups decide which policy to lobby for and then, in a second stage, engage in a contest over the proposed policies. Our main result is that competition over endogenously determined policies induces strategic restraint that reduces polarization and, in turn, wasteful lobbying activities.     

Nepotism,Discrimination, and the Persistence of Utility-Maximizing,Owner-Operated Firms: Comment

A recent thoughtful paper by Singell and Thornton (thereafter ST) in the Southern Economic Journal deviates in definitions, modeling, and a result from the traditional literature on tastes for discrimination and nepotism that originates with Becker and Arrow. This comment provides a critique of these three aspects of the ST analysis. In particular, it shows that ST's astonishing result that discrimination will persist in a competitive labor market is unjustified, ST's unconventional definitions of owners with unbiased and biased preferences are wrong, and ST's unique modeling of discrimination and nepotism is unsupported.     

Two-settlement Systems for Electricity Markets under Network Uncertainty and Market Power

We analyze welfare and distributional properties of a two-settlement system consisting of a spot market over a two-node network and a single energy forward contract. We formulate and analyze several models which simulate joint dispatch of energy and transmission resources coordinated by a system operator. The spot market is subject to network uncertainty, which we model as a random capacity derating of an important transmission line. Using a duopoly model, we show that even for small probabilities of congestion (derating), forward trading may be substantially reduced, and the market power mitigating effect of forward markets (as shown in Allaz and Vila 1993) may be nullified to a great extent. There is a spot transmission charge reflecting transportation costs from location of generation to a designated hub whose price is the underlying for the forward contract. This alleviates some of the incentive problems associated with the forward market in which spot-market trading is residual. We find that the reduction in forward trading is due to the segregation of the markets in the constrained state, and the absence of natural incentives for generators to commit to more aggressive behavior in the spot market (the strategic substitutes effect). In our analysis, we find that the standard assumption of no-arbitrage across forward and spot markets leads to very little contract coverage, even for the case with no congestion. We present an alternative view of the market where limited intertemporal arbitrage enables temporal price discrimination by competing duopolists. In this framework, we assume that all of the demand shows up in the forward market (or that the market is cleared against an accurate forecast of the demand), and the forward price is determined using a market clearing condition.     

Hedging Strategies of Financial Intermediaries: Pricing Options with a Bid-Ask Spread

This paper uses a model similar to the Boyle-Vorst and Ritchken-Kuo arbitrage-free models for the valuation of options with transactions costs to determine the maximum price to be charged by the financial intermediary writing an option in a non-auction market. Earlier models are extended by recognizing that, in the presence of transactions costs, the price-taking intermediary devising a hedging portfolio faces a tradeoff: to choose a short trading interval with small hedging errors and high transactions costs, or a long trading interval with large hedging errors and low transactions costs. The model presented here also recognizes that when transactions costs induce less frequent portfolio adjustments, investors are faced with a multinomial distribution of asset returns rather than a binomial one. The price upper bound is determined by selecting the trading frequency that will equalize the marginal gain from decreasing hedging errors and the marginal cost of transactions.     

Priority Network Access Pricing for Electric Power

We propose a priority-pricing scheme for zonal access to the electric power grid that is uniform across all buses in a zone. The independent system operator (ISO) charges bulk power traders a per unit ex ante transmission access fee. The zonal access fee serves as an access insurance premium that entitles a bulk power trader to either physical injection of one unit of energy or a compensation payment. The access fee per MWh depends on the injection zone and a self-selected strike price that serves as an insurance deductible that determines the scheduling priority of the insured transaction and the compensation level in case of curtailment. Inter-zonal transactions are charged (or credited) with an additional ex post congestion fee equal to the differences in zonal spot prices. The compensation for curtailed transactions equals the difference between the realized zonal spot price and the selected strike price (deductible level). The ISO manages congestion so as to minimize net compensation payments and thus, curtailment probabilities increase with strike price and for any particular strike price may vary from bus to bus. We calculate the rational expectations equilibrium for three-, four- and six-node systems and demonstrate that the efficiency losses of the proposed second best scheme relative to the efficient dispatch solutions are modest.