Multimarket Competition and Welfare Effects of Price discrimination

The paper investigates the effects on welfare of price discrimination when a multimarket seller faces competition in one of its two markets. With respect to uniform pricing, price discrimination changes competition in such a way, that even with linear demands, price discrimination can be welfare-improving, both under strategic substitutes and strategic complements.welfare analysis, price discrimination, multimsarket competition

Welfare Effects of Third-Degree Price Discrimination: Ippolito Meets Schmalensee and Varian

Based on a pioneering work by Ippolito (1980) we construct a simple model wich allows the welfare effects of third-degree price discrimination to be well understood and explained. The decomposition of the change in welfare into a misallocation effect and an output effect has advantages over the well-established analysis by Schamalensee (1981) and Varian (1985). In particular, our approach provides a graphic analysis which clarifies the welfare analysis of third-degree price discrimination.

The influence of nitrate leaching through unsaturated soil on groundwater pollution in an agricultural area of the Basque country: a case study

The average nitrate concentration in the groundwater of the Vitoria-Gasteiz (Basque Country) quaternary aquifer rose from 50 mg NO3−/l during 1986 to over 200 mg/l in 1995, which represents an increase of some 20 mg NO3−/l per year. From 1995 to 2002, the nitrate concentration of the groundwater slightly decreased. Nitrategroundwaterpollution during the period 1986–1993 was the result of the abusive use of fertilizers and of the modification in the recharge patterns of the aquifer from surface water sources. From 1993 onwards, apart from a possible rationalization in fertilizer use, the change in the origin of water for irrigation and wetland restoration (water is taken now from artificial pools outside the quaternary aquifer) must be explained in order to account for the observed decrease in nitrate concentration in the groundwater. The water of the aquifer and of the unsaturated zone were studied in two experimental plots (one of them cultivated and the other uncultivated) for 18 months (January 1993–June 1994), during the period of maximum contamination, to evaluate the effect of fertilizers on soil water and on the water in the saturated zone. The soil water was sampled using soil lysimeters at various depths. The volumetric water content of the soil was measured at the same depths using time domain reflectrometry (TDR) probes. Samples of groundwater were taken from a network of wells on the aquifer scale, two located close to the two experimental plots. The temporal evolution of nitrate concentrations in soil solutions depends on the addition of fertilizers and on soilnitrateleaching by rain. During episodes of intense rain (>50 mm in a day), the groundwater deposits are recharged with water coming from the leaching of interstitial soil solutions, causing an increase in the groundwaternitrate concentrations. The mass of nitrate leached from the cultivated zone is five times higher than that of the nitrate leached from the uncultivated zone (1147 kg NO3−/ha in the cultivated sector as against 211 kg NO3−/ha in the uncultivated sector), although part of the nitrate leached into the soil had been previously deposited by the rise of the water table. If we consider that the level of groundwater input is similar in both plots, we may conclude that 964 kg NO3−/ha circulated towards the groundwater in the cultivated zone during the period under study, representing 87% of the nitrate applied to the soil in the form of fertilizer during that period

Comparison of Selection Methods in On-line Distributed Evolutionary Robotics

In this paper, we study the impact of selection methods in the context of on-line on-board distributed evolutionary algorithms. We propose a variant of the mEDEA algorithm in which we add a selection operator, and we apply it in a taskdriven scenario. We evaluate four selection methods that induce different intensity of selection pressure in a multi-robot navigation with obstacle avoidance task and a collective foraging task. Experiments show that a small intensity of selection pressure is sufficient to rapidly obtain good performances on the tasks at hand. We introduce different measures to compare the selection methods, and show that the higher the selection pressure, the better the performances obtained, especially for the more challenging food foraging task

Groundwater pollution in quaternary aquifer of Vitoria - Gasteiz (Basque Country, Spain)

As a result of diverse changes in land use and in water-resource management in the high basin of the Zadorra River (Basque Country), an important loss of water resources and an intense contamination by nitrogen compounds has taken place. The purpose of this paper is to detail the land transformations that have taken place on the aquifer since the 1950s: increase of drainage network, change from dry to irrigated farming, and diversion of rivers at the aquifer unit inlet. Furthermore, we analyze the impact of these transformations on the hydrodynamics and water quality of this aquifer system

On the strategic choice of spatial price policy: the role of the pricing game rules

In this paper, whe show that the strategic choice of spatial price policy under duopoly crucially depends on the rules of price competition. Thisse and Vives (1988) show that spatial price discrimination is a dominant strategy when the mill pricing firm is the leader and the discriminatory firm is the follower. When the leader-follower roles are reversed we find that equilibrium pricing policies depend on the consumer's reservation value. The pricing policy game has two equilibria in pure strategies, either both firms price uniformly (f.o.b.) or both firms price discriminate, when the reservation value is low. For intermediate levels of the reservation value, price discrimination is a dominant strategy and the pricing policy game is similar to a Prisoner's Dilemma. When the consumer reservation value is large enough we obtain asymmetric equilibria in which one firm prices according to f.o.b. and the other price discriminates. We also analyze the case of simultaneous price competition and find a mixed strategies equilibrium for the price competition subgame such that the pricing policy game has two equilibria in pure strategies, either both firms price uniformly or both firms price discriminate.spatial price discrimination, price policy

Product Differentiation with Consumer Arbitrage

Also published as Working Paper DFAEII 2003-01spatial price discrimination, product differentiation, personal arbitrage

Asymptotics in the schema of simple varieties of trees

We study the functional equation y(x) = xA(y(x)) satisfied by the generating functions in the schema of simple varieties of trees. The radii of convergence r, R of y, A respectively satisfy y(r) <= R. In the subcritical case (y(r) < R), y_n behaves asymptotically as C·r^(-n)·n^(-3/2). In the critical case (y(r)=R), we approach the problem of determining the asymptotics of a_n when the information of y(x) is well known. To that end, we give sufficient conditions that ensure that A(z) can be extended to a delta domain around its dominant singularity R, which is needed to be able to apply the transfer theorem when determining the asymptotics. We do a similar analysis for the equation y(x) = x+ B(y(x)), which appears in the additive schema of simple varieties of trees. The general framework we propose includes the three examples of extension to a delta domain of the functions A(z) and B(z) encountered in the literature so far

On the economics of the "meeting competition defense" under the Robinson-Patman Act

Documento de trabajoIn this paper we analyze the welfare effects of third-degree price discrimination when competitive pressure varies across markets. In particular, we study the economic aspects of the Robinson-Patman Act associated with the “meeting competition defense.” Using equilibrium models, the main result we find is that this defense might be used successfully in cases of primary line injury precisely when it should not be used, namely when price discrimination reduces social welfare. This result obtains both when discrimination appears in the final good market and when it is used in the intermediate goods market. We also find that these results may drastically change under secondary line injury.The Ministerio de Economía y Competitividad (ECO2012-31626) and from the Departamento de Educación, Política Lingüística y Cultura del Gobierno Vasco (IT869-13