Microlocal Analysis of Some Isospectral Deformations

We study the microlocal structure of the examples of isospectral deformations of Riemannian manifolds given by D. DeTurck and C. Gordon in [DeT-G1]. The Schwartz kernel of the intertwining operators considered by them may be written as an oscillatory integral with a singular phase function and product type amplitude. In certain instances, we identify them as belonging to the space of Fourier integral operators associated with various pairwise intersecting Lagrangians. After formulating a class of operators incorporating the most relevant features of the operators above, we establish a composition calculus for this class and show that is not necessary to introduce new Lagrangians in the composition.Publicad

Distribution of Income and Aggregation of Demand.

We show that, under certain regularity conditions, if the distribution of income IS price independent and satisfies a condition on the shape of its graph, then total market demand, F(p), is monotone, i.e., given two positive prices p, and q, one has (p - q) . (F(p) - F(q))

Efficiency, Monotonicity and Rationality in Public Goods Economies

In economies with public goods, we provide a necessary and sufficient condition for the existence of cost monotonic selections from the set of Pareto optimal and individualIy ratiollal allocations. Such selections exist if and only if the preCerences of the agents satisfy what we call the equal ordering property. This requirement is very restrictive in the context of more than one public good. However, whenever it holds any such mechanism must choose an egalitarian equivalent allocation

Welfarism in economic domains

In economies with public goods, and agents with quasi-linear preferences, we give a characterization of the welfare egalitarian correspondence in terms of three axioms: Pareto optimality, symmetry, and solidarity. This last property requires that an increase in the willingness to pay for the public goods of some of the agents should not decrease the welfare of any of them.Publicad

Tax enforcement problems

We study an income tax enforcement problem using a principal-agent model where the government sets the tax and inspection functions. These are announced to the agents and there is no commitment problem. The penalty function for dishonest taxpayers is given exogenously and satisfies certain social norms. We prove that, for a large family of penalty functions, this policy is such that honesty implies regressiveness. This result does not depend on the fact that agents know the true probability of inspection.Publicad

Income taxation, uncertainty and stability

This paper develops a political model to analyze the stability of income tax schedules. It is assumed that agents perceive any proposed alternative tax policy as more uncertain than the status quo. A tax policy is stable if it is a Condorcet winner. It is well known that in a model without uncertainty the existence of such a policy is very rare. We show, however, that in real cases this might not be a serious problem since small amounts of uncertainty can bring stability to the status quo. It is also shown that linear tax functions can only be stable in economies with very egalitarian income distributions and high taxation levelsPublicad

Income taxation, uncertainty and stability.

This paper develops a political model to analyze the stability of income tax schedules. It is assumed that agents perceive any proposed alternative tax policy as more uncertain than the status quo. A tax policy is stable if it is a Condorcet winner. It is well known that in a model without uncertainty the existence of such a policy is very rare. We show, however, that in real cases this might not be a serious problem since small amounts of uncertainty can bring stability to the status quo. It is also shown that linear tax functions can only be stable in economies with very egalitarian income distributions and high taxation levelsMajority voting; Income taxation; Uncertainty; Status quo;

Tax enforcement problems.

We study an income tax enforcement problem using a principal-agent model where the government sets the tax and inspection functions. These are announced to the agents and there is no commitment problem. The penalty function for dishonest taxpayers is given exogenously and satisfies certain social norms. We prove that, for a large family of penalty functions, this policy is such that honesty implies regressiveness. This result does not depend on the fact that agents know the true probability of inspection.

Distribution of Income and Aggregation of Demand

We show that, under certain regularity conditions, if the distribution of income IS price independent and satisfies a condition on the shape of its graph, then total market demand, F(p), is monotone, i.e., given two positive prices p, and q, one has (p - q) . (F(p) - F(q)) < O. Similar assumptions on the distributions of endowments, yield a restricted monotonicity property on aggregate excess demand, where, now, wealth is determined by market prices. This is enough, however, to obtain uniqueness and stability of equilibrium for our Walrasian pure exchange model

Endogenous platforms : the case of many parties.

We analyze existence of equilibrium in a one-dimensional model of endogenous party platforms and more than two parties. The platforms proposed by parties depend on their membership composition. The policy implemented is a function of the different proposals and the vote distribution among such proposals. It is shown that if voters are sincere there is always an equilibrium regardless of the number of parties. In the case of strategic voting behavior, existence of equilibrium can be shown provided a subadditivity condition on the outcome function holds.