Inequality over the business cycle: Estimating income risk using micro-data on consumption

We use CEX repeated cross-section data on consumption and income, to evaluate the nature of increased income inequality in the 1980s and 90s. We decompose unexpected changes in family income into transitory and permanent, and idiosyncratic and aggregate components, and estimate the contribution of each component to total inequality. The model we use is a linearized incomplete markets model, enriched to incorporate risk-sharing while maintaining tractability. Our estimates suggest that taking risk sharing into account is important for the model fit; that the increase in inequality in the 1980s was mainly permanent; and that inequality is driven almost entirely by idiosyncratic income risk. In addition we find no evidence for cyclical behavior of consumption risk, casting doubt on Constantinides and Duffie s (1995) explanation for the equity premium puzzle.

Hybrid consumption paths in the attribute space: A model and application with scanner data

This paper presents and estimates a dynamic choice model in the attribute space considering rational consumers. In light of the evidence of several state-dependence patterns, the standard attribute-based model is extended by considering a general utility function where pure inertia and pure variety-seeking behaviors can be explained in the model as particular linear cases. The dynamics of the model are fully characterized by standard dynamic programming techniques. The model presents a stationary consumption pattern that can be inertial, where the consumer only buys one product, or a variety-seeking one, where the consumer shifts among varied products.We run some simulations to analyze the consumption paths out of the steady state. Underthe hybrid utility assumption, the consumer behaves inertially among the unfamiliar brandsfor several periods, eventually switching to a variety-seeking behavior when the stationary levels are approached. An empirical analysis is run using scanner databases for three different product categories: fabric softener, saltine cracker, and catsup. Non-linear specifications provide the best fit of the data, as hybrid functional forms are found in all the product categories for most attributes and segments. These results reveal the statistical superiority of the non-linear structure and confirm the gradual trend to seek variety as the level of familiarity with the purchased items increases.

Revenue management under general discrete choice model of consumer behavior

Customer choice behavior, such as 'buy-up' and 'buy-down', is an importantphe-nomenon in a wide range of industries. Yet there are few models ormethodologies available to exploit this phenomenon within yield managementsystems. We make some progress on filling this void. Specifically, wedevelop a model of yield management in which the buyers' behavior ismodeled explicitly using a multi-nomial logit model of demand. Thecontrol problem is to decide which subset of fare classes to offer ateach point in time. The set of open fare classes then affects the purchaseprobabilities for each class. We formulate a dynamic program todetermine the optimal control policy and show that it reduces to a dynamicnested allocation policy. Thus, the optimal choice-based policy caneasily be implemented in reservation systems that use nested allocationcontrols. We also develop an estimation procedure for our model based onthe expectation-maximization (EM) method that jointly estimates arrivalrates and choice model parameters when no-purchase outcomes areunobservable. Numerical results show that this combined optimization-estimation approach may significantly improve revenue performancerelative to traditional leg-based models that do not account for choicebehavior.

Economic rationality and ethical behavior

This paper argues that economic rationality and ethical behavior cannotbe reduced one to the other, casting doubts on the validity of formulaslike 'profit is ethical' or 'ethics pays'. In order to express ethicaldilemmas as opposing economic interest with ethical concerns, we proposea model of rational behavior that combines these two irreducible dimensions in an open but not arbitrary manner. Behaviors that are neither ethicalnor profitable are considered irrational (non-arbitrariness). However,behaviors that are profitable but unethical, and behaviors that are ethicalbut not profitable, are all treated as rational (openness). Combiningethical concerns with economic interest, ethical business is in turn anoptimal form of rationality between venality and sacrifice.Because every one prefers to communicate that he acts ethically, ethicalbusiness remains ambiguous until some economic interest is actuallysacrificed. We argue however that ethical business has an interest indemonstrating its consistency between communication and behavior by atransparent attitude. On the other hand, venal behaviors must remainconfidential to hide the corresponding lack of consistency. Thisdiscursive approach based on transparency and confidentiality helpsto further distinguish between ethical and unethical business behaviors.

Testing calibrated general equilibrium models

This paper illustrates the philosophy which forms the basis of calibrationexercises in general equilibrium macroeconomic models and the details of theprocedure, the advantages and the disadvantages of the approach, with particularreference to the issue of testing ``false'' economic models. We provide anoverview of the most recent simulation--based approaches to the testing problemand compare them to standard econometric methods used to test the fit of non--lineardynamic general equilibrium models. We illustrate how simulation--based techniques can be used to formally evaluate the fit of a calibrated modelto the data and obtain ideas on how to improve the model design using a standardproblem in the international real business cycle literature, i.e. whether amodel with complete financial markets and no restrictions to capital mobility is able to reproduce the second order properties of aggregate savingand aggregate investment in an open economy.

Does money matter in shaping domestic business cycles? An international investigation (with appendices)

We study the contribution of money to business cycle fluctuations in the US,the UK, Japan, and the Euro area using a small scale structural monetary business cycle model. Constrained likelihood-based estimates of the parameters areprovided and time instabilities analyzed. Real balances are statistically importantfor output and inflation fluctuations. Their contribution changes over time. Models giving money no role provide a distorted representation of the sources of cyclicalfluctuations, of the transmission of shocks and of the events of the last 40 years.

On the origins of electoral systems and political parties. The role of elections in multi-member districts

The old, understudied electoral system composed of multi-member districts, open ballot and plurality rule is presented as the most remote scene of the origin of both political parties and new electoral systems. A survey of the uses of this set of electoral rules in different parts of the world during remote and recent periods shows its wide spread. A model of voting by this electoral system demonstrates that, while it can produce varied and pluralistic representation, it also provides incentives to form factional or partisan candidacies. Famous negative reactions to the emergence of factions and political parties during the 18th and 19th centuries are reinterpreted in this context. Many electoral rules and procedures invented since the second half of the 19th century, including the Australian ballot, single-member districts, limited and cumulative ballots, and proportional representation rules, derived from the search to reduce the effects of the originating multi-member district system in favor of a single party sweep. The general relations between political parties and electoral systems are restated to account for the foundational stage here discussed.

World population growth and fertility patterns, 1960-2000. A simple model explaining the evolution of world's fertility during the second half of the 20th Century

In this paper we attempt to describe the general reasons behind the world populationexplosion in the 20th century. The size of the population at the end of the century inquestion, deemed excessive by some, was a consequence of a dramatic improvementin life expectancies, attributable, in turn, to scientific innovation, the circulation ofinformation and economic growth. Nevertheless, fertility is a variable that plays acrucial role in differences in demographic growth. We identify infant mortality, femaleeducation levels and racial identity as important exogenous variables affecting fertility.It is estimated that in poor countries one additional year of primary schooling forwomen leads to 0.614 child less per couple on average (worldwide). While it may bepossible to identify a global tendency towards convergence in demographic trends,particular attention should be paid to the case of Africa, not only due to its differentdemographic patterns, but also because much of the continent's population has yet toexperience improvement in quality of life generally enjoyed across the rest of theplanet.

Business cycles, unemployment insurance and the calibration of matching models

This paper theoretically and empirically documents a puzzle that arises when an RBC economy with a job matching function is used to model unemployment. The standard model can generate sufficiently large cyclical fluctuations in unemployment, or a sufficiently small response of unemployment to labor market policies, but it cannot do both. Variable search and separation, finite UI benefit duration, efficiency wages, and capital all fail to resolve this puzzle. However, either sticky wages or match-specific productivity shocks can improve the model's performance by making the firm's flow of surplus more procyclical, which makes hiring more procyclical too.

Ignorance promotes competition: An auction model with endogenous private valuations

We study a situation in which an auctioneer wishes to sell an object toone of N risk-neutral bidders with heterogeneous preferences. Theauctioneer does not know bidders preferences but has private informationabout the characteristics of the ob ject, and must decide how muchinformation to reveal prior to the auction. We show that the auctioneerhas incentives to release less information than would be efficient andthat the amount of information released increases with the level ofcompetition (as measured by the number of bidders). Furthermore, in aperfectly competitive market the auctioneer would provide the efficientlevel of information.

Endogenous labor market participation and the business cycle

Existing models of equilibrium unemployment with endogenous labor market participation are complex, generate procyclical unemployment rates and cannot match unemployment variability relative to GDP. We embed endogenous participation in a simple, tractable job market matching model, show analytically how variations in the participation rate are driven by the cross-sectional density of home productivity near the participation threshold, andhow this density translates into an extensive-margin labor supply elasticity. A calibration of the model to macro data not only matches employment and participation variabilities but also generates strongly countercyclical unemployment rates. With some wage rigidity the model also matches unemployment variations well. Furthermore, the labor supply elasticity implied by our calibration is consistent with microeconometric evidence for the US.

Inventory-routing model, for a multi-period problem with stochastic and deterministic demand

The need for integration in the supply chain management leads us to considerthe coordination of two logistic planning functions: transportation andinventory. The coordination of these activities can be an extremely importantsource of competitive advantage in the supply chain management. The battle forcost reduction can pass through the equilibrium of transportation versusinventory managing costs. In this work, we study the specific case of aninventory-routing problem for a week planning period with different types ofdemand. A heuristic methodology, based on the Iterated Local Search, isproposed to solve the Multi-Period Inventory Routing Problem with stochasticand deterministic demand.

Monetary policy and exchange rate volatility in a small open economy

We lay out a small open economy version of the Calvo sticky price model, and show how the equilibrium dynamics can be reduced to simple representation in domestic inflation and the output gap. We use the resulting framework to analyze the macroeconomic implications of three alternative rule-based policy regimes for the small open economy: domestic inflation and CPI-based Taylor rules, and an exchange rate peg. We show that a key difference amongthese regimes lies in the relative amount of exchange rate volatility that they entail. We also discuss a special case for which domestic inflation targeting constitutes the optimal policy, and where a simple second order approximation to the utility of the representative consumer can be derived and used to evaluate the welfare losses associated with the suboptimal rules.

Endogenous business cycles and stabilization policies

The paper reports results on the effects of stylized stabilization policies on endogenously created fluctuations. A simple monetary model with intertemporally optimizing agents is considered. Fluctuations in output may occur due to fluctuations in labor supply which are again caused by volatile expectations which are ``self fulfilling'', i.e. correct given the model. It turns out that stabilization policies that are sufficiently countercyclical in the sense that government spending (on transfers or demand) depends sufficiently strongly negatively on GNP-increases can stabilize the economy at a monetary steadystate for an arbitrarily low degree of distortion of that steady state. Such stabilization has unambiguously good welfare effects and can be achieved without features such as positive lump sum taxation or negative income taxation as part of the stabilization policy.