Veronika Grimm

Low Price Equilibrium in Multi-Unit Auctions: The GSM Spectrum Auction in Germany

The second-generation GSM spectrum auction in Germany is probably the most clear cut example of a low price outcome in a simultaneous ascending-bid auction. The present paper gives an account of the events, describes the auction rules and market conditions, and provides a theoretical explanation of low price equilibria in simultaneous, ascending-bid auctions. In particular it is shown that the low price equilibrium that implements the efficient allocation is the unique perfect equilibrium of that game.

An experiment on learning in a multiple games environment

We study how players learn to make decisions if they face many different games. Games are drawn randomly from a set of either two or six games in each of 100 rounds. If either there are few games or if extensive summary information is provided (or both) convergence to the unique Nash equilibrium generally occurs. Otherwise this is not the case. We demonstrate that there are learning spillovers across games but participants learn to play strategically equivalent games in the same way. Our design and analysis allow us to distinguish between different sources of complexity and theoretical models of categorization.(This abstract was borrowed from another version of this item.)

Bidding Behaviour in Multi-Unit Auctions – An Experimental Investigation*

We present laboratory experiments of five different multi-unit auction mechanisms. Two units of a homogeneous object were auctioned off among two bidders with flat demand for two units. We test whether expected demand reduction occurs in open and sealed-bid uniform-price auctions. We also test revenue equivalence for these auctions as well as for the Ausubel, the Vickrey and the discriminatory sealed-bid auction. Furthermore, we compare the five mechanisms with respect to the efficient allocation of the units.

Mechanisms for Efficient Voting with Private Information About Preferences

In games of conflict, players typically have an incentive to exaggerate their interests. This concerns issues ranging from negotiations between political parties to conflict resolution within marriages. We experimentally study this problem using a simple voting game where information about preferences is private. With random matching, subjects overwhelmingly follow the dominant strategy to exaggerate their preferences. The exogenous linking mechanism by Jackson and Sonnenschein (2007) captures nearly all achievable efficiency gains. Repeated interaction in various settings, which could allow endogenous linking mechanisms to evolve, leads to significant gains in truthful representation and efficiency only when players can choose their partners.

The Third Generation (Umts) Spectrum Auction in Germany

The third generation UMTS auction in Germany raised an enormous amount of revenue, and at the same time achieved a more competitive market structure than other UMTS auctions in Europe. The present paper explains the design of that auction, and presents a game theoretic explanation of observed events during the crucial phase of that auction, which have puzzled several observers. In addition, the paper evaluates the merit of the German UMTS auction design, relative to the English design, that was predominantly employed in Europe.

Transmission and generation investment in electricity markets: The effects of market splitting and network fee regimes

We propose an equilibrium model that allows to analyze the long-run impact of the electricity market design on transmission line expansion by the regulator and investment in generation capacity by private firms in liberalized electricity markets. The model incorporates investment decisions of the transmission system operator and private firms in expectation of an energy-only market and cost-based redispatch. In different specifications we consider the cases of one vs. multiple price zones (market splitting) and analyze different approaches to recover network cost—in particular lump sum, generation capacity based, and energy based fees. In order to compare the outcomes of our multilevel market model with a first best benchmark, we also solve the corresponding integrated planner problem. Using two test networks we illustrate that energy-only markets can lead to suboptimal locational decisions for generation capacity and thus imply excessive network expansion. Market splitting heals these problems only partially. These results are valid for all considered types of network tariffs, although investment slightly differs across those regimes.

Investment Incentives and Electricity Spot Market Competition

In this paper we analyze investment decisions of strategic firms that anticipate competition on many consecutive spot markets with fluctuating (and possibly uncertain) demand. We study how the degree of spot market competition affects investment incentives and welfare and provide an application of the model to electricity market data. We show that more competitive spot market prices strictly decrease investment incentives of strategic firms. The effect can be severe enough to even offset the beneficial impact of more competitive spot markets on social welfare. Our results obtain with and without free entry. The analysis demonstrates that investment incentives necessarily have to be taken into account for a serious assessment of electricity spot market design.

Uniqueness of market equilibrium on a network: A peak-load pricing approach

In this paper we establish conditions under which uniqueness of market equilibrium is obtained in a setup where prior to trading of electricity, transmission capacities between different market regions are fixed. In our setup, firms facing fluctuating demand decide on the size and location of production facilities. They make production decisions constrained by the invested capacities, taking into account that market prices (partially) reflect scarce transmission capacities between the different market zones. For this type of peak-load pricing model on a network we state general conditions for existence and uniqueness of the market equilibrium and provide a characterization of equilibrium investment and production. The presented analysis covers the cases of perfect competition and monopoly—the case of strategic firms is approximated by a conjectural variations approach. Our result is a prerequisite for analyzing regulatory policy options with computational multilevel equilibrium models, since uniqueness of the equilibrium at lower levels is of key importance when solving these models. Thus, our paper contributes to an evolving strand of literature that analyzes regulatory policy based on computational multilevel equilibrium models and aims at taking into account individual objectives of various agents, among them not only generators and customers but also, e.g., the regulator deciding on network expansion.

Price Regulation under Demand Uncertainty

In this paper we provide a taxonomy of price cap regulation in oligopoly under demand uncertainty. We show that independently of the nature of uncertainty high price caps always increase production and welfare as compared to setting no price cap. We also derive conditions on the demand distribution under which a price cap close to marginal cost can be optimal and when it is not. For demand distributions with an increasing hazard rate we show that price regulation under demand uncertainty can be viewed as a well behaved extension of the analysis for deterministic demand. For this class of distributions we characterize the optimal price cap, which is unique and may or may not be close to marginal cost. Our general framework nests the limit case of deterministic demand as well as results by Earle et al. (2007), who have shown that standard arguments supporting the imposition of price caps may break down in the presence of demand uncertainty.

Overcoming Incentive Constraints? The (In-)Effectiveness of Social Interaction

We experimentally study behavior in a simple voting game where players have private information about their preferences. With random matching, subjects overwhelmingly follow the dominant strategy to exaggerate their preferences. Applying the linking mechanism suggested by Jackson and Sonnenschein (2005) captures nearly all achievable efficiency gains. Repeated interaction leads to significant gains in truthful representation and efficiency only if players can choose their partners.