The dynamics of price elasticity of demand in the presence of reference price effects

The authors derive an expression for the price elasticity of demand in the presence of reference price effects that includes a component resulting from the presence of gains and losses in consumer evaluations. The effect of reference price is most noticeable immediately after a price change, before consumers have had time to adjust their reference price. As a result, immediate-term price elasticity is higher than long-term elasticity, which describes the response of demand long after a price change, when reference price effects are negligible. Furthermore, because of the differential effect of gains and losses, immediate-term price elasticity for price increases and price decreases is not equal. The authors provide a quantitative definition for the terms immediate term and long term, using the average interpurchase time and the discrete “memory” parameter. Practical consequences of the distinction between immediate- and long-term elasticities for the estimation and use of elasticity values are discussed. Gadi Fibich (fibich@math.tau.ac.il) is an associate professor in the Department of Applied Mathematics at Tel Aviv University. This research grew out of his interest in applications of mathematical modeling to economics and management science. He is currently working on auction theory. Arieh Gavious (ariehg@bgumail.bgu.ac.il) is a senior lecturer in the Department of Industrial Engineering at Ben Gurion University, Israel. His interest is in application of game theory to economics and management science problems. His current interest is in auction theory. Oded Lowengart (odedl@bgumail.bgu.ac.il) is a senior lecturer in the Department of Business Administration at Ben Gurion University, Israel. His research interests are in the areas of modeling pricing effects on consumer behavior at both aggregate and disaggregate levels, product positioning, and market share forecasting and diagnostics.     

Rational panics and stock market crashes

This paper offers an explanation for stock market crashes which focuses on the role of rational but uninformed traders. We show that uninformed traders can precipitate a price crash because as prices decline, they surmise that informed traders received negative information, which leads them to reduce their demand for assets and drive the price of stocks even lower. The model yields several implications, such as that crashes can occur even when the fundamentals are strong, and that the magnitude of the crash depends on the fraction of uninformed investors and the amount of unsophisticated passive investing present in the market.     

Revenue equivalence in asymmetric auctions

The Revenue Equivalence Theorem is generalized to the case of asymmetric auctions in which each player's valuation is drawn independently from a common support according to his/her distribution function.     

An elementary proof of the common maximal bid in asymmetric first-price and all-pay auctions

We prove that the maximal bid in asymmetric first-price and all-pay auctions is the same for all bidders. Our proof is elementary, and does not require that bidders are risk neutral, or that the distribution functions of their valuations are independent or smooth.     

Information Acquisition in Financial Markets

Previous work on information and financial markets has focused on a special set of assumptions: agents have exponential utility, and random variables are normally distributed. These assumptions are often necessary to obtain closed-form solutions. We present an example with alternative assumptions, and demonstrate that some of the conclusions from previous literature fail to hold. In particular, we show that in our example, as more agents acquire information, prices do not necessarily become more informative, and agents may have greater incentive to acquire information. Learning can therefore be a strategic complement, allowing for the possibility of multiple equilibria.     

Credit market frictions and the allocation of resources over the business cycle

In a seminal paper, Davis and Haltiwanger (1990) demonstrated that recessions are associated with increased job reallocation. The conventional view has interpreted this as evidence of “cleansing”: less productive jobs are destroyed in recessions, and resources are reallocated to more productive uses. This paper argues instead that in the presence of credit market frictions, reallocation might go the other way, directing resources from more efficient to less efficient uses. This will occur if more efficient production arrangements are also more vulnerable to credit constraints. I show that this pattern arises endogenously in an equilibrium model, and offer some evidence that firms with higher output per worker tend to borrow more, suggesting they are more vulnerable to credit constrains.     

Earnings inequality and the business cycle

Economists have long viewed recessions as contributing to increasing inequality. However, this conclusion is largely based on data from a period in which inequality was increasing over time. This paper examines the connection between long-run trends and cyclical variation in earnings inequality. We develop a model in which cyclical and trend inequality are related, and find that in our model, recessions tend to amplify long-run trends, i.e. they involve more rapidly increasing inequality when long-run inequality is increasing, and more rapidly decreasing inequality when long-run inequality is decreasing. In support of this prediction, we present evidence that during the first half of the 20th century, when earnings inequality was generally declining, earnings disparities indeed appeared to fall more rapidly in downturns, at least among workers at the top of the earnings distribution.     

El sindicalismo israelí ante el empleo atípico. El fenómeno de la liminalidad permanente

Los comités de empresa israelíes se están adaptando a la economía neoliberal y a las transformaciones laborales concomitantes con una doble postura: por un lado tratan de hacer frente a esta reformulación del capitalismo para salvaguardar los derechos de los trabajadores, y por otro aceptan cada vez más las formas atípicas de empleo. Esta contradicción los sitúa en un estadio de «liminalidad» permanente, en el que sus funciones se reducen a una mera búsqueda de compromisos y soluciones ad hoc. Como consecuencia, su lucha contra los efectos adversos del empleo atípico sigue siendo puntual y fragmentada, lo que contribuye a consolidar estas modalidades de empleo.     

Estimating mobility rates in search models with initial condition problems

Previous empirical work on job search has proposed different approaches to estimating mobility rates assumed in models of search. However, these methods either only work for specific models of wage determination, or else require that we know the initial distribution of productivity for workers in our sample. In this paper we show it is possible to estimate mobility rates without having to restrict attention to models in which wages are constant over the course of a job or to assume that the initial distribution of productivity is known. More generally, the approach we propose allows us to freely estimate one degree of unobserved heterogeneity, be it in initial conditions or mobility rates. Applying our results to data from the NLSY suggests that the theoretical restrictions on the initial distribution of productivity implied by the standard model can overstate the extent of frictions to upward mobility.     

The Sullying Effect of Recessions

Previous work has established that recessions involve a "cleansing" effect, so that in downturns, only high productivity jobs remain. But empirical evidence suggests job quality is procyclical: jobs created in recessions are likely to be low-paying and temporary. This paper modifies previous models by adding on-the-job search, which leads to an additional "sullying" effect. Calibration of the model suggests this offsetting sullying effect is likely to be much larger than the cleansing effect, and can account for the procyclical match quality we observe in the data.