Computational Efficiency Requires Simple Taxation

We characterize the communication complexity of truthful mechanisms. Our departure point is the well known taxation principle. The taxation principle asserts that every truthful mechanism can be interpreted as follows: every player is presented with a menu that consists of a price for each bundle (the prices depend only on the valuations of the other players). Each player is allocated a bundle that maximizes his profit according to this menu. We define the taxation complexity of a truthful mechanism to be the logarithm of the maximum number of menus that may be presented to a player. Our main finding is that in general the taxation complexity essentially equals the communication complexity. The proof consists of two main steps. First, we prove that for rich enough domains the taxation complexity is at most the communication complexity. We then show that the taxation complexity is much smaller than the communication complexity only in "pathological" cases and provide a formal description of these extreme cases. Next, we study mechanisms that access the valuations via value queries only. In this setting we establish that the menu complexity -- a notion that was already studied in several different contexts -- characterizes the number of value queries that the mechanism makes in exactly the same way that the taxation complexity characterizes the communication complexity. Our approach yields several applications, including strengthening the solution concept with low communication overhead, fast computation of prices, and hardness of approximation by computationally efficient truthful mechanisms

The Design of Capital Income Taxation: Reflections on the Mirrlees Review

This commentary reflects on the recommendations of the Mirrlees Review on tax reform with a special focus on capital income taxation. Regarding the alternatives of moving to a consumption based tax system, the commentary discusses the relative merits of choosing an ACE system (allowance for corporate equity) rather than a cash-flow tax on the company level. It reviews the arguments in favour of full elimination of tax on the normal return to savings at the personal level which contrasts with alternative tax reform proposals recommending a positive but low and flat tax rate on personal capital income. It also discusses how existing computational models would have to be extended for a meaningful quantification of the gains and costs of implementing a tax reform along the lines of the Mirrlees Review.Fundamental tax reform, consumption based tax system

Optimal response to a transitory demographic shock in Social Security financing

We examine the optimal policy response to a transitory demographic shock that affects negatively the financing of retirement pensions. In contrast to existing literature, we endogenously determine optimal policies rather than exploring implications of exogenous parametric policies. Our approach identifies optimal strategies of the social security administration to guarantee the financial sustainability of existing retirement pensions in a Pareto improving way. Hence, no cohort will pay the cost of the demographic shock. We find that the optimal strategy is based in the following ingredients: elimination of compulsory retirement, a change in the structure of labor income taxation and a temporary increase in the level of government debt.Social security ; Pensions

Optimal response to a transitory demographic shock in Social Security financing

The authors consider a transitory demographic shock that affects negatively the financing of retirement pensions-that is, workers either would have to pay more or retirees would receive less. In contrast to the existing literature, the authors endogenously determine optimal policies rather than explore the implications of exogenous parametric responses. Their approach identifies optimal strategies of the Social Security Administration to guarantee the financial sustainability of existing retirement pensions in a Pareto-improving way. Hence, no cohort will pay the cost of the demographic shock. The authors find that the optimal strategy is based on the following ingredients: elimination of compulsory retirement, a change in the structure of labor income taxation, and a temporary increase in the level of government debt.Social security ; Pensions

The Welfare Gains of Age Related Optimal Income Taxation

Using a calibrated overlapping generations model we quantify the welfare gains of an age dependent income tax. Agents face uncertainty regarding future abilities and can by saving transfer consumption across periods. The welfare gain of switching from an age-independent to an age-dependent nonlinear tax amounts in our benchmark model to around three percent of GDP. The gains are particularly high when there are restrictions on debt policy. The gains of using a nonlinear- as opposed to a linear tax are even larger. Surprisingly, it is of secondary importance to optimally choose the tax on interest income.labor income taxation, capital income taxation, age-dependent taxes, OLG model

Discretionary Policy versus Non-Discretionary Policy in the Economic Adjustment Process

The study aims to examine the concept of automatic fiscal stabilization in the context of macroeconomic adjustment policies. To this end, first a conceptual distinction between discretionary public adjustment policies and non-discretionary ones is achieved. Second, sufficient and necessary attributes for an automatic fiscal stabilizer are identified and examined, in order to obtain a definition of this instrument. The whole research approach is characterized by a logical and abstract way of thinking, to provide a general and non-contextual result. Finally, a general mechanism of action of automatic fiscal stabilizers is proposed, by introducing the basic concepts of action base and of action rate of such an instrument.sustainability, fiscal policy, automatic fiscal stabilizers, discretionary versus nondiscretionary, principle of the minimal action

A simplified MOLP algorithm: The MOLP-S procedure

Linear Programming;Algorithm;computer science

Macroeconomics with frictions

This article is a progress report on research that attempts to include one type of market incompleteness and frictions in macroeconomic models. The focus of the research is the absence of insurance markets in which individual-specific risks may be insured against. The article describes some areas where this type of research has been and promises to be particularly useful, including consumption and saving, wealth distribution, asset markets, business cycles, and fiscal policies. The article also describes work in each of these areas that was presented at a conference sponsored by the Federal Reserve Bank of Minneapolis in the fall of 1993. ; Reprinted in the Quarterly Review, Summer 1997 (v. 21, no. 3)Macroeconomics

Microsimulation as a tool for evaluating redistribution policies

During the last twenty years, microsimulation models have been increasingly applied in qualitative and quantitative analysis of public policies. This paper provides a discussion on microsimulation techniques and their theoretical background as a tool for the analysis of public policies with particular attention to redistribution and social policies. Basic principles in using microsimulation models and interpreting their results are analyzed, with particular emphasis on tax incidence, redistribution and poverty analysis. Social welfare analysis permitted by microsimulation techniques is also discussed. Finally, the paper points to limits of present approaches and directions for future research.microsimulation ; evaluation of public policies ; optimal taxation ; poverty and inequality

The Distribution of Tax Burdens: An Introduction

This paper summarizes important developments in tax incidence analysis over the past forty years. We mark the date of the beginning of modern tax incidence analysis with the publication of Harberger (1962) and discuss the relation of subsequent work to this seminal paper.