Abstract
This paper examines how firms should allocate their advertising budgets between consumers who have a high preference for their products (i.e., strong segment) and those who prefer competing products (i.e., weak segment). Targeted advertising transmits relevant information to otherwise uninformed consumers and it is used as a price discrimination device. With targeted advertising and price discrimination, we find that, when the attractiveness of the weak segment is low, each firm advertises more intensively in its strong segment. The same result arises when the attractiveness of the weak segment is high and advertising is sufficiently expensive. Interestingly, when the attractiveness of the weak segment is high but advertising costs are sufficiently low, it is optimal for each firm to advertise more intensively in its weak segment. The paper also investigates how advertising strategies and equilibrium profits are affected by price discrimination. Compared with uniform pricing, firms can increase or reduce the intensity of advertising targeted to each segment when price discrimination is allowed. Furthermore, when the attractiveness of the weak market is high, price discrimination boosts firms' profits provided that advertising costs are sufficiently low. The reverse happens when advertising costs are high.

Abstract
This paper studies inefficiencies arising in oligopolies subject to environmental regulation based on tradable emission permits. We propose a duopoly model of upstream-downstream strategic competition: in the permits market a leader sets the price, whereas in the output market Cournot competition occurs. We find that strategic interaction in the output market gives rise to an additional distortion in the permits market where both firms adopt rival's cost-rising' strategies to gain a competitive advantage in the output market. As a result, the price of permits is always higher than firms' marginal abatement costs.

Abstract
A free daily newspaper distributes news to readers and sells ad-space to advertisers, having private information about its audience. For a given number of distributed copies, depending on the type of audience (favorable or unfavorable), the newspaper may either have a large readership or a small readership. A large readership provides a greater return to advertisers, because ads are visualized by more people. A favorable audience has also the advantage of requiring a lower distribution cost (for a given number of distributed copies), because readers are willing to exert more effort to obtain a copy of the free newspaper and are less likely to reject a copy that is handed to them. We find that when the audience is unfavorable, the number of distributed copies and the price of ad-space coincide with those of the perfect information scenario. In contrast, if the audience is favorable, the newspaper prints extra copies to send a credible signal to the advertisers that the audience is favorable. Overprinting is not necessarily welfare-detrimental since readers benefit from the existence of additional copies.

Abstract
There is no consensus on the method to set transmission tariffs for natural gas. The entry-exit system is widely used in European markets because it is cost reflective, it allows the network users to separately book capacity for entry and exit points, beyond its pro-competitiveness characteristics. Some authors, however, defend the adoption of the postage stamp (where a single tariff is charged regardless of the origin of the gas), due to its simplicity. Our goal is to compare these two mechanisms of transmission tariff with respect to the impacts on welfare. We find that the welfare effects crucially depend on the size of the internal market and the fixed costs supported by the incumbent firm. If the domestic market is sufficiently large and there are imports from abroad, consumer surplus is higher under the postage stamp system.

Abstract
This paper investigates the expansion of the network of a monopolist firm that produces a durable good and is also involved in the corresponding aftermarket. We characterize the Markov Perfect Equilibrium of the continuous time dynamic game played by the monopolist and the forward-looking consumers, under the assumption that consumers benefit from the subsequent expansion of the network. The paper contributes to the theoretical discussion on the validity of the Coase conjecture, analyzing whether Coase's prediction that the monopolist serves the market in a "twinkling of an eye" remains valid in our setup. We conclude that the equilibrium network development may actually be gradual, contradicting Coase's conjecture. We find that a necessary condition for such a result is the existence of aftermarket network effects that accrue (at least partly) to the monopolist firm.

Abstract
We consider a nondurable good monopolist that collects data on its customers in order to profile them and subsequently practice price discrimination on returning cus-tomers. The monopolist's price discrimination scheme is leaky in the sense that an endogenous fraction of consumers choose to incur a privacy cost to conceal their identity when they return in the following periods. We characterize the Markov perfect equili-brium of the game under two alternative customer profiling regimes: full information acquisition (FIA) and purchase history information (PHI). In both cases, we find that, contrary to what could be expected, the monopolist's aggregate profit is not monotoni-cally increasing in the level of the privacy cost, but a U-shaped function of it, leading to ambiguous profit effects: a reduction in privacy costs increases the fraction of customers who choose to be anonymous (detrimental profit effect), but it also softens the firm's introductory price, reducing the pace at which prices targeted to new customers fall over time (positive profit effect). When comparing results under FIA and PHI, we find that market expansion is faster, and more customers conceal their identity under FIA than under PHI. Equilibrium profits are also higher in the FIA case. Although equili-brium profits are U-shaped functions of the privacy cost in both profiling regimes, they tend to be globally decreasing with the privacy cost under PHI and globally increasing under FIA.