A Note On Long Memory Time Series

This note presents the fractional integrated processes which are the main models used to describe long memory phenomena.¹ Section 1 briefly defines the concept of fractional integration, shows the fundamental properties and provides a short summary of the estimation methods. Section 2 consists of a survey of their extensions in order to model long-term cycles.     

Linear Inequality Methods to Enforce Partnerships under Uncertainty: An Overview

We review different (generic) conditions on stochastic outcome functions to enforce either efficient or nearly efficient partnerships. Their logical relationship is explored. Two kinds of conditions are considered. However, the property for an action profile to be “compatible” plays a crucial role in both kinds. Also, two kinds of enforcement mechanisms are considered: enforcement through utility transfers and enforcement through repetition.Journal of Economic LiteratureClassification Numbers: D2, D7.     

A reconsideration of the link between vertical externality and managerial incentives

Previous research revealed that the strategic role of delegation contracts disappears if two quantity‐setting firms outsource input production to a monopolistic supplier. I show that this role is restored if the assumption of a downstream duopoly is relaxed. Thus, delegation contracts allow downstream profit‐maximizing owners to commit their firms to a behavior that differs from their preferences. This behavior varies nonmonotonically with the number of firms in the downstream market. Corresponding deviations from profit maximization are larger if the upstream monopolist makes a price precommitment. But little to no deviation occurs if the number of firms is large.     

Liability insurance under the negligence rule

We incorporate the concept of evidentiary standard to the analysis of the negligence rule under liability insurance and court errors. When the postaccident evidence is privately contractible and not too noisy, efficiency is achieved by both strict liability and a negligence rule with appropriate due care and evidentiary standards. When the evidence is not directly contractible, trial outcomes represent useful contractible information for the risk‐incentives tradeoff in the liability insurance policy. Strict liability is then inefficient and dominated by the negligence rule. The negligence rule can itself be improved upon by decoupling damages from the harm suffered by the victim.     

Rewrites of an Expert System—Lessons Learned

One component of the 1986 Tax Law was to require taxpayers to file information returns on magnetic media if the quantity to be filed was sufficiently large. A waiver from this filing requirement was possible under hardship and other criteria, and could be obtained by filing a form with the Internal Revenue Service (IRS). Initially, the processing of waiver requests was accomplished manually by several relatively high-level analytical personnel. The IRS's Artificial Intelligence Laboratory (AI Lab) created an Expert System to automate the process. An initial prototype was developed in OPS5+, an AI language, and the system was used on all waiver requests for Forms 1099 for Tax Year 1987, demonstrating feasibility and capability. The system was expanded in the following year, and used on waiver requests for all form types. For Tax Year 1989 the system was rewritten in LEVEL5, so that it could be more easily maintained by in-house personnel. However, implementation problems forced a rapid rewrite, using CLIPPER, a dBase III+ compiler language. This version was subsequently used for all waiver requests for Tax Years 1989 and 1990. Presently, one clerical person can handle all of the waivers. This paper deals with the reasons and ramifications of this language-shell-language transition.     

Political issues in inland waterways port development: prospects for regionalization

In the vast scientific literature on maritime transport, one theme appears neglected: the juridico-political framework in port development. We first examine how the jurisdictional control influences the allocation of resources and financial responsibilities. Second, we carefully evaluate conventional theoretical explanations of the process of port development as it generates important consequences on port policy formulation. We suggest that the concept of the port transition needs to be positioned within a new paradigm of the regional economy. Third, by focusing on three case studies namely France, China and Canada, we provide an understanding of institutional structure and how they reflect tendencies in port development. We then investigate regional flows, particularly the role of offshore, inshore and coastal traffic. Fourth, we present policy options for regionalization of ports. Fifth, we explore the regional elements of the port transition and provide an appreciation of the new role of the State in port development policies. The paper concludes on the adoption of new paradigm in port development strategies.     

The theory of double jeopardy

This paper discusses the relevance of the behavioral theory of “double jeopardy,” developed by a sociologist, to the prediction of aggregate consumer behavior. The author describes the testing of this relationship by the use of national consumer panel data and more than a quarter-million purchases. He concludes that the more popular a brand becomes, the more loyal to it will be its buyers.     

Ranking of information systems in agency models: an integral condition

Summary. We provide a condition for ranking of information systems in agency problems. The condition has a straightforward economic interpretation in terms of the sensitivity of a cumulative distribution with respect to the agent's effort. The criterion is shown to be equivalent to the mean preserving spread condition on the likelihood ratio distributions. Received: November 10, 1999; revised version: February 17, 2000