Web usage mining approaches to page recommendation and restructuring

As an increasing number of Web sites such as e-businesses consist of an increasing number of pages, users find it more difficult to rapidly reach their own target pages. Ill-structured design of Web sites also prevents the users from rapidly accessing the target pages. In this paper, we describe two complementary approaches to Web usage mining as a key solution to these issues. First, we describe an adaptable recommendation system called the L-R system, which constructs user models by classifying the Web access logs and by extracting access patterns based on the transition probability of page accesses and recommends the relevant pages to the users based on both the user models and the Web structures. We have evaluated the prototype system and have obtained the positive effects. Second, we describe another approach to constructing user models, which clusters Web access logs based on access patterns. The user models also help to discover unexpected access paths corresponding to ill-formed Web site design. Copyright © 2003 John Wiley & Sons, Ltd.     

Impossibility of Nash implementation in two-person economies

In this note, we prove two impossibility results of Nash implementation in two-person economies. First, we will show the non-existence of continuous and balanced mechanisms which implement the Walrasian correspondence. Second, by adding a convexity assumption of mechanisms, we present the impossibility of continuous implementation of Pareto optimal and individually rational allocations in balanced way. Received: 16 April 1996 / Accepted: 25 April 1997     

Price dynamics, retail chains and inflation measurement

We use a large scanner price dataset to study grocery price dynamics. Previous analyses based on store scanner data emphasize differences in price dynamics across products. However, we also document large differences in price movements across different grocery store chains. A variance decomposition indicates that characteristics at the level of the chains (as opposed to individual stores) explain a large fraction of the total variation in price dynamics. Thus, retailer characteristics are found to be crucial determinants of heterogeneity in pricing dynamics, in addition to product characteristics. We empirically explore how the price dynamics we document affect price index measures.     

Adoption and policy implications of Japan’s new corporate governance practices after the reform

In this paper we explain the process and policy implications of Japanese firms’ adoption of recently reformed corporate governance practices. We use a selective adaptation framework in doing so. We present some qualitative predictions about the possible outcome of their adoption process. One advantage of our approach is that we can describe various aspects of the evolutionary process of Japan’s corporate governance reform as a system in a consistent manner, rather than as independent pieces. Our predictions provide policy implications and are empirically testable. Japan’s post-bubble corporate governance reform has been extensive and involves the enactment and revisions of many relevant laws and affected institutions. Japan’s aim has been to install US-like practices (the de facto global standard), with these practices replacing the now tarnished bank-centered practices, and to facilitate Japanese industry in regaining global competitiveness. However, we show that Japanese businesses’ adoption of US practices has been selective and efficiency and other policy implications of such behavior are potentially dysfunctional.     

Macroeconomic Implications of Term Structures of Interest Rates Under Stochastic Differential Utility with Non-Unitary EIS

This paper proposes a continuous-time term-structure model under stochastic differential utility with non-unitary elasticity of intertemporal substitution (EIS, henceforth) in a representative-agent endowment economy with mean-reverting expectations on real output growth and inflation. Using this model, we make clear structural relationships among a term structure of real and nominal interest rates, utility form and underlying economic factors (in particular, inflation expectation). Notably, we show that, if (1) the EIS is less than one, (2) the agent is comparatively more risk-averse relative to time-separable utility, (3) short-term interest rates are pro-cyclical, and (4) the rate of expected inflation is negatively correlated with the rate of real output growth and its expected rate, then a nominal yield curve can have a low instantaneous riskless rate and an upward slope.     

A contingent claim analysis of closed-end fund premia

We estimate contingent claims that replicate monthly net asset value (NAV) payoffs from closed-end funds. A claim's theoretical value is obtained by martingale pricing methods. The resulting net present value (NPVS) sequence is the theoretical premia sequence that is compared to the actual market premia sequence. The theoretical premia, like actual premia, are uncorrelated with NAV returns and are positively autocorrelated due to autocorrelation in the pricing information. However, there is poor correspondence between the theoretical and actual premia that seems due to the market's systematic errors in estimating a fund's management value. Risky arbitrage may be available to insiders.     

Price Versus Quantity in a Duopoly with a Unilateral Effect and with Bargaining over Managerial Contracts

This study examines the endogenous choice of each firm’s strategic contract, that is, a price contract or a quantity contract, in a duopoly in which their demand functions are asymmetric when the content of their managerial contracts is determined through bargaining between the owner and the manager. The degree of asymmetry between their demand functions corresponds to the relation between the goods they produce. In contrast to the case wherein each firm’s delegation parameter is determined through profit maximization, we show that the quantity competition cannot become the equilibrium market structure when the bargaining power of the manager relative to that of the owner is sufficiently low. In particular, when the relation between the two goods is complementary, two asymmetric market structures can be observed in equilibrium. Furthermore, we consider the situation in which the relative bargaining power of the manager to that of the owner within each firm is different between the two firms.