Dealership market: Market-making with inventory

This study considers the problem of a price-setting monopolistic market-maker in a dealership market where the stochastic demand and supply are depicted by price-dependent Poisson processes [following Garman (1976)]. The crux of the analysis is the dependence of the bid-ask prices on the market-maker's stock inventory position. We derive the optimal policy and its characteristics and compare it to Garman's. The results are shown to be consistent with some conjectures and observed phenomena, like the existence of a ‘preferred’ inventory position and the downward monotonicity of the bid-ask prices. For linear demand and supply functions we derive the behavior of the bid-ask spread and show that the transaction-to-transaction price behavior is intertemporally dependent. However, we prove that it is impossible to make a profit on this price dependence by trading against the market-maker. Thus, in this situation, serially dependent price-changes are consistent with the market efficiency hypothesis.     

Crossing Networks and Dealer Markets: Competition and Performance

This paper studies the interaction between dealer markets and a relatively new form of exchange, passive crossing networks, where buyers and sellers trade directly with one another. We find that the crossing network is characterized by both positive ('liquidity') and negative ('crowding') externalities, and we analyze the effects of its introduction on the dealer market. Traders who use the dealer market as a 'market of last resort' can induce dealers to widen their spread and can lead to more efficient subsequent prices, but traders who only use the crossing network can provide a counterbalancing effect by reducing adverse selection and inventory holding costs.     

A NOTE ON THE GENERALIZED MULTIBETA CAPM

The unified beta theory of Connor (1984) requires that the market portfolio be well diversified in a given factor structure. Wei (1988) extended Connor's results without relying on this assumption. This note provides an alternative to Wei's result by assuming that residuals from the projection of asset return on a set of k factors follow a joint elliptical distribution.     

The CAPM is Alive and Well: A Review and Synthesis

Mean-Variance (M-V) analysis and the CAPM are derived in the expected utility framework. Behavioural Economists and Psychologists (BE&P) advocate that expected utility is invalid, suggesting Prospect Theory as a substitute paradigm. Moreover, they show that the M-V rule, which is the foundation of the CAPM, is not always consistent with peoples' choices. Thus, BE&P cast doubt on the validity of expected utility paradigm and of the M-V rule, hence the CAPM is theoretically questionable. In addition, there is very little empirical support to the CAPM. We show in this study that the CAPM is theoretically valid even when one accepts the BE&P framework and even when expected utility is invalid. Moreover, within the BE&P framework there is a strong experimental support for the CAPM.