Robust Repeated Auctions under Heterogeneous Buyer Behavior

We study revenue optimization in a repeated auction between a single seller and a single buyer. Traditionally, the design of repeated auctions requires strong modeling assumptions about the bidder behavior, such as it being myopic, infinite lookahead, or some specific form of learning behavior. Is it possible to design mechanisms which are simultaneously optimal against a multitude of possible buyer behaviors? We answer this question by designing a simple state-based mechanism that is simultaneously approximately optimal against a $k$-lookahead buyer for all $k$, a buyer who is a no-regret learner, and a buyer who is a policy-regret learner. Against each type of buyer our mechanism attains a constant fraction of the optimal revenue attainable against that type of buyer. We complement our positive results with almost tight impossibility results, showing that the revenue approximation tradeoffs achieved by our mechanism for different lookahead attitudes are near-optimal

Individual choice of pension arrangement as a pension reform strategy

The paper examines social security (public pension) reforms in which the programme is partially shifted from a public unfunded basis to a private, prefunded, basis. It focuses on reforms where individuals have a choice in switching from public funded to private unfunded programmes (as in the Ñ£ontracting outÒ scheme in the UK), or where some individuals are forced to join the funded scheme, or reforms which combine both these options. The welfare consequences of such reform strategies are analysed both from an individual and a macroeconomic perspective. The paper also examines whether individuals respond Ѳationally' to the incentives inherent in such programmes.

Reducing Deforestation and Trading Emissions: Economic Implications for the post-Kyoto Carbon Market

This paper quantitatively assesses the economic implications of crediting carbon abatement from reduced deforestation for the emissions market in 2020 by linking a numerical equilibrium model of the global carbon market with a dynamic partial equilibrium model of the forestry sector. We find that integrating avoided deforestation in international emissions trading considerably decreases the costs of post-Kyoto climate policy – even when accounting for conventional abatement options of developing countries under the CDM. At the same time, tropical rainforest regions receive substantial net revenues from exporting carbon-offset credits to the industrialized world. Moreover, reduced deforestation can increase environmental effectiveness by enabling industrialized countries to tighten their carbon constraints without increasing mitigation costs. Regarding uncertainties of this future carbon abatement option, we find both forestry transaction costs and deforestation baselines to play an important role for the post-Kyoto carbon market. --Climate Change,Kyoto Protocol,Emissions Trading,Deforestation

Selling to a No-Regret Buyer

We consider the problem of a single seller repeatedly selling a single item to a single buyer (specifically, the buyer has a value drawn fresh from known distribution $D$ in every round). Prior work assumes that the buyer is fully rational and will perfectly reason about how their bids today affect the seller's decisions tomorrow. In this work we initiate a different direction: the buyer simply runs a no-regret learning algorithm over possible bids. We provide a fairly complete characterization of optimal auctions for the seller in this domain. Specifically: - If the buyer bids according to EXP3 (or any "mean-based" learning algorithm), then the seller can extract expected revenue arbitrarily close to the expected welfare. This auction is independent of the buyer's valuation $D$, but somewhat unnatural as it is sometimes in the buyer's interest to overbid. - There exists a learning algorithm $\mathcal{A}$ such that if the buyer bids according to $\mathcal{A}$ then the optimal strategy for the seller is simply to post the Myerson reserve for $D$ every round. - If the buyer bids according to EXP3 (or any "mean-based" learning algorithm), but the seller is restricted to "natural" auction formats where overbidding is dominated (e.g. Generalized First-Price or Generalized Second-Price), then the optimal strategy for the seller is a pay-your-bid format with decreasing reserves over time. Moreover, the seller's optimal achievable revenue is characterized by a linear program, and can be unboundedly better than the best truthful auction yet simultaneously unboundedly worse than the expected welfare

Central bank Financial Independence

Central bank independence is a multifaceted institutional design. The financial component has been seldom analysed. This paper intends to set a comprehensive conceptual background for central bank financial independence. Quite often central banks are modelled as robot like maximizers of some goal. This perspective neglects the fact that central bank functions are inevitably deployed on its balance sheet and have effects on its income statement. A financially independent central bank exhibits the adequate balance sheet structure and earnings generation capacity to efficiently perform its functions. From a long term perspective, as far as the demand for banknotes is maintained seignorage waters down any central bank financial independence concern. However, from a short term perspective central bank financial vulnerability may condition its effective independence. Vulnerability may be real or accounting based. However, no matter its origin, institutional solutions are needed to minimize their impact. Adequate capitalization turns out to be a key issue. Alternatively, contingent capital in the form of institutional arrangements to bear central bank losses may be a (second- best) solution. The paper analyses in the context of simple VAR model the interplay between capitalization, accounting rules and dividend distribution. This analysis is preceded by a thorough discussion of the risk return profile of central banks net return on assets. Three main conclusions shape the input to the capitalization model. Central banks return on assets can be very volatile from a short term perspective. From a medium term perspective, natural earnings generation cycles dampen down volatility. On average, central banks net return on assets typically exhibits a discount over government debt financing cost. These observations shape the central bank financing planning problem as follows. Namely, the size of the discount relative to the social costs that would arise in case of a lack of central bank independence, along with central bank exposure to risks and the volatility thereof, determine the incentives of the government to maintain an excess of financial assets in the form of central bank capital. Actually, the working of smoothing mechanisms operating across time on central banks earnings leads to a distinction between short term and medium term capital, i.e. the optimum capital solution is a band. In the same vein, the need to maintain optimal consistence between central bank financial strength and dividends distribution policy leads also to smoothing proposals for pay out policy.Central Banking Capital, Independence, Accounting, Profits