Foreclosing competition through access charges and price discrimination

This article analyzes competition between two asymmetric networks, an incumbent and a new entrant. Networks compete in non-linear tariffs and may charge different prices for on-net and off-net calls. Departing from cost-based access pricing allows the incumbent to foreclose the market in a profitable way. If the incumbent benefits from customer inertia, then it has an incentive to insist on the highest possible access markup even if access charges are reciprocal and even in the absence of actual switching costs. If instead the entrant benefits from customer activism, then foreclosure is profitable only when switching costs are large enough.Networks; benefits; costs; customer;

Effect of feed on cholesterol concentration and oxidation products development of longissimus dorsi muscle from Iberian pigs

peer-reviewedThe effect of dietary free-range feeding or supplementation with copper and/or vitamin E in confinement on total cholesterol, neutral and polar lipids and cholesterol oxidation of the longissimus dorsi muscle from Iberian pigs was studied. Free-range fed pigs had higher (P=0.001) contents of γ-tocopherol and lower concentrations of α-tocopherol in the muscle than pigs fed diets supplemented with 100 mg/kg vitamin E. The total cholesterol content of the muscle was not significantly affected by the diets. However, the cholesterol:phospholipid ratio was higher (P<0.05), and consequently the membrane fluidity was lower, in the free-range fed pigs than in the pigs fed in confinement with either copper-supplemented (P<0.05) or vitamin E-supplemented (P<0.01) diets. The proportion of saturated fatty acids in phospholipids was greater (P<0.05) in the free-range fed group, which suggests metabolic regulation to maintain membrane structure. Free-range feeding produced higher levels of free fatty acids (P<0.01), lysophosphatidylcholine (P<0.05) and phosphatidylserine (P<0.01) and lower cholesterol esters (P<0.01) and sphingomyelin (P<0.05) in the muscle than the other groups. The ratios of phosphatidylethanolamine:phosphatidylcholine and sphingomyelin: phosphatidylcholine, which are indicators of membrane fluidity, were not significantly affected in any group. Dietary α-tocopheryl acetate supplementation produced lower β-epoxide (P<0.01), 7β-OH (P<0.05), and total cholesterol oxides (P<0.01) in cooked muscle after refrigerated display than in the other groups. These results indicate that supplementation with dietary α-tocopheryl acetate is more effective in reducing cholesterol oxidation than free-range feeding in cooked muscle from Iberian pigs. In evaluating oxidation, the composition of the muscle and meat treatment have to be considered as well as membrane fluidity.This research was funded by the European Project AIR-CT94-1577 (DIETOX

Optimal education and pensions in an endogenous growth model

It is well known that, in OLG economies with life-cycle saving and exogenous growth, competitive equilibria will in general fail to achieve optimality and may even be dynamically inefficient. This is a consequence of individuals accumulating amounts of physical capital that differ from the level which would maximize welfare along a balanced growth path (the Golden Rule). With human capital, a second potential source of departure from optimality arises, to wit: individuals may not choose the correct amount of education investment. However, the Golden Rule concept, widely used in exogenous growth frameworks, has not found its way into endogenous growth models. In this paper, we propose to recover the Golden Rule of physical and also human capital accumulation. The optimal policy to decentralize the Golden Rule balanced growth path when there are no constraints for individuals to finance their education investments is also characterized. It is shown that it involves positive pensions and negative education subsidies (i.e., taxes)endogenous growth, human capital, intergenerational transfers, education policy

On welfare criteria and optimality in an endogenous growth model

In this paper we explore the consequences for optimality of a social planner adopting two different welfare criteria. The framework of analysis is an OLG model with physical and human capital. We first show that, when the SWF is a discounted sum of individual utilities defined over consumption per unit of natural labour, the precise cardinalization of the individual utility function becomes crucial for the characterization of the social optimum. Also, decentralizing the social optimum requires an education subsidy. In contrast, when the SWF is a discounted sum of individual utilities defined over consumption per unit of efficient labour, the precise cardinalization of preferences becomes irrelevant. More strikingly, along the optimal growth path, education should be taxed.endogenous growth, human capital, intergenerational transfers, education policy