Price Squeezes and Imputation Tests on Next Generation Access Networks

A vertically integrated firm that wholesales to its retail rivals can, if it has sufficient market power, set the margin between its retail and wholesale prices so as to harm its rivals. Conventionally, an imputation test is used to determine whether such behavior is being undertaken. Such tests are common in electronic communications, and the EC calls for their potentially intensive ex ante application in the supply of NGANs. This paper shows that while imputation tests are helpful analytical tools for understanding the nature of price squeezes, difficulties associated with implementation, which are sharp in an NGAN context, can make them misleading in practice. Instead, price squeezes are best dealt with through the rigorous comparison of expected outcomes, given the alleged anticompetitive behavior, with the outcomes expected in that behavior’s absence. Such analysis is not suited to ex ante application.price squeeze, imputation tests, next generation access networks, vertical discrimination, electronic communications, regulation

Grant support and exporting activity.

This paper investigates whether government support can act to increase exporting activity. We use a uniquely rich data set on Irish manufacturing plants and employ an empirical strategy that combines a non-parametric matching procedure with a difference-in-differences estimator in order to deal with the potential selection problem inherent in the analysis. Our results suggest that if grants are large enough they can encourage already exporting firms to compete more effectively on the international market. However, there is little evidence that grants encourage non-exporters to start exporting.Exportsubvention; Wirtschaftspolitische Wirkungsanalyse; Exporthandel; Irland;exporting; subsidies; matching; difference-in-differences;

Cool Core Bias in Sunyaev-Zel'dovich Galaxy Cluster Surveys

Sunyaev-Zeldovich (SZ) surveys find massive clusters of galaxies by measuring the inverse Compton scattering of cosmic microwave background off of intra-cluster gas. The cluster selection function from such surveys is expected to be nearly independent of redshift and cluster astrophysics. In this work, we estimate the effect on the observed SZ signal of centrally-peaked gas density profiles (cool cores) and radio emission from the brightest cluster galaxy (BCG) by creating mock observations of a sample of clusters that span the observed range of classical cooling rates and radio luminosities. For each cluster, we make simulated SZ observations by the South Pole Telescope and characterize the cluster selection function, but note that our results are broadly applicable to other SZ surveys. We find that the inclusion of a cool core can cause a change in the measured SPT significance of a cluster between 0.01% - 10% at z > 0.3, increasing with cuspiness of the cool core and angular size on the sky of the cluster (i.e., decreasing redshift, increasing mass). We provide quantitative estimates of the bias in the SZ signal as a function of a gas density cuspiness parameter, redshift, mass, and the 1.4 GHz radio luminosity of the central AGN. Based on this work, we estimate that, for the Phoenix cluster (one of the strongest cool cores known), the presence of a cool core is biasing the SZ significance high by ~ 6%. The ubiquity of radio galaxies at the centers of cool core clusters will offset the cool core bias to varying degrees.Comment: 8 pages, 4 figures, accepted to Ap

A Central Limit Theorem for Repeating Patterns

This note gives a central limit theorem for the length of the longest subsequence of a random permutation which follows some repeating pattern. This includes the case of any fixed pattern of ups and downs which has at least one of each, such as the alternating case considered by Stanley in [2] and Widom in [3]. In every case considered the convergence in the limit of long permutations is to normal with mean and variance linear in the length of the permutations

Multinational Companies, Backward Linkages and Labour Demand Elasticities

This paper investigates the link between nationality of ownership and wage elasticities of labour demand at the level of the plant. In particular, we examine whether labour demand in multinationals becomes less elastic with respect to the wage if the plant has backward linkages with the local economy. Our empirical evidence, based on a rich plant level dataset, shows that the extent of local linkages indeed reduces the wage elasticity of labour demand. This result is economically important and holds for a number of different specifications.labour demand, elasticities, linkages, multinational companies