Arbitrage and Walrasian equilibrium economies with limited information

Equilibrium Theory;economic theory

Equilibrium with co-ordination and exchange institutions: A comment

Equilibrium Theory;econometrics

Liquidity Provision, Ambiguous Asset Returns and the Financial Crisis

For an economy with dysfunctional intertemporal financial markets the financial sector is modelled as a competitive banking sector oering deposit contracts. In a setting similar to Allen and Gale (1998) properties of the optimal liquidity provision are analyzed for illiquid assets with ambiguous returns. In the context of the model, ambiguity | i.e. incalculable risk | leads to dynamically inconsistent investor behaviour. If the financial sector fails to recognize the presence of ambiguity, unanticipated fundamental crises may occur, which are incorrectly blamed on investors 'loosing their nerves' and 'panicing'. The basic mechanism of the current financial crisis resembles a banking panic in the presence of ambiguous asset returns. The combination of providing additional liquidity and supporting distressed financial institutions implements the regulatory policy suggested by the model. A credible commitment to such 'bail-out policy' does not create a moral hazard problem. Rather, it implements the second best efficient outcome by discouraging excessive caution. Reducing ambiguity by increasing stability, transparency and predictability | as suggested by ordo-liberalism and the 'Freiburger Schule’ | enhances ex-ante welfare.Financial Intermediation, Liquidity, Ambiguity, Choquet Expected Utility, Financial Crisis

Liquidity and Ambiguity: Banks or Asset Markets?

We study the impact of ambiguity on two alternative institutions of financial intermediation in an economy where consumers face uncertain liquidity needs. The ambiguity the consumers experience is modeled by the degree of confidence in their additive beliefs. We analyze the optimal liquidity allocation and two institutional settings for implementing this allocation: a secondary asset market and a bank deposit contract. For full confidence we obtain the well-known result that consumers prefer the bank deposit contract over the asset market, since the former can provide the optimal cross subsidy for consumers with high liquidity needs. With increasing ambiguity this preference will be reversed: the asset market is preferred, since it avoids inefficient liquidation if the bank reserve holdings turn out to be suboptimal.Financial institutions, Liquidity, Ambiguity, Choquet Expected Utility.

Liquidity and Ambiguity: Banks or Asset Markets?

We study the impact of ambiguity on two alternative institutions of financial intermediation in an economy where consumers face uncertain liquidity needs. The ambiguity the consumers experience is modeled by the degree of confidence in their additive beliefs. We analyze the optimal liquidity allocation and two institutional settings for implementing this allocation: a secondary asset market and a bank deposit contract. For full confidence we obtain the well-known result that consumers prefer the bank deposit contract over the asset market, since the former can provide the optimal cross subsidy for consumers with high liquidity needs. With increasing ambiguity this preference will be reversed: the asset market is preferred, since it avoids inecient liquidation if the bank reserve holdings turn out to be suboptimal.

Hierarchical trade and downstream information

Economics;econometrics

Closed-loop two-echelon repairable item systems

In this paper we consider closed loop two-echelon repairable item systems with repair facilities both at a number of local service centers (called bases) and at a central location (the depot). The goal of the system is to maintain a number of production facilities (one at each base) in optimal operational condition. Each production facility consists of a number of identical machines which may fail incidentally. Each repair facility may be considered to be a multi-server station, while any transport from the depot to the bases is modeled as an ample server. At all bases as well as at the depot, ready-for-use spare parts (machines) are kept in stock. Once a machine in the production cell of a certain base fails, it is replaced by a ready-for-use machine from that base's stock, if available. The failed machine is either repaired at the base or repaired at the central repair facility. In the case of local repair, the machine is added to the local spare parts stock as a ready-for-use machine after repair. If a repair at the depot is needed, the base orders a machine from the central spare parts stock to replenish its local stock, while the failed machine is added to the central stock after repair. Orders are satisfied on a first-come-first-served basis while any requirement that cannot be satisfied immediately either at the bases or at the depot is backlogged. In case of a backlog at a certain base, that base's production cell performs worse. To determine the steady state probabilities of the system, we develop a slightly aggregated system model and propose a special near-product-form solution that provides excellent approximations of relevant performance measures. The depot repair shop is modeled as a server with state-dependent service rates, of which the parameters follow from an application of Norton's theorem for Closed Queuing Networks. A special adaptation to a general Multi-Class MDA algorithm is proposed, on which the approximations are based. All relevant performance measures can be calculated with errors which are generally less than one percent, when compared to simulation results. \u