Trees and decisions

Summary. The traditional model of sequential decision making, for instance, in extensive form games, is a tree. Most texts define a tree as a connected directed graph without loops and a distinguished node, called the root. But an abstract graph is not a domain for decision theory. Decision theory perceives of acts as functions from states to consequences. Sequential decisions, accordingly, get conceptualized by mappings from sets of states to sets of consequences. Thus, the question arises whether a natural definition of a tree can be given, where nodes are sets of states. We show that, indeed, trees can be defined as specific collections of sets. Without loss of generality the elements of these sets can be interpreted as representing plays. Therefore, the elements can serve as states and consequences at the same time.Received: 23 January 2003, Revised: 2 November 2003, JEL Classification Numbers: C72, D70. Correspondence to: Klaus RitzbergerWe are grateful to Larry Blume, Ariel Rubinstein, Jörgen Weibull, an anonymous referee, and seminar participants at the universities of Vienna, Salamanca, and Heidelberg for helpful comments. Financial support from the Austrian Science Fund (FWF) under project P15281 is also gratefully acknowledged.     

Top dominance and the possibility of strategy-proof stable solutions to matching problems

Summary This paper explores the possibility of designing strategy-proof mechanisms yielding satisfactory solutions to the marriage and to the college admissions problem. Our first result is negative. We prove that no strategy-proof mechanism can always choose marriages that are individually rational and Pareto efficient. This strengthens a result by Roth (1982) showing that strategy-proof mechanisms cannot always select stable marriages. The result also applies, a fortiori, to college admissions. Since finding difficulties with strategy-proofness is quite an expected result, we then address a second question which is classical within the incentives literature. Are there restrictions on the preferences of agents under which strategy-proof and stable mechanisms do exist? We identify a nontrivial restriction on the domain of preferences, to be called top dominance, under which there exist strategy-proof and stable mechanisms for both types of matching problems. The mechanisms turn out to be exactly those that derive from the most classical algorithms in the literature; namely, the women's optimal, the men's optimal and the student's optimal. Finally, top dominance is shown to be essentially necessary, as well as sufficient, for the existence of strategy-proof stable matching mechanisms.This work is partially supported by grant PB 89-0294, from the Directión General de Investigatión Ciencia y Tecnología of the Spanish Ministerio de Educación y Ciencia. Salvador Barberà is also grateful to the Instituto de Estudios Fiscales. This research was initiated while both authors were visting GREMAQ, Université des Sciencies Sociales, Toulouse, whose hospitality is gratefully acknowledged. The paper extends results that were circulated as GREMAQ W.P. 91.22.232. We are grateful to Matthew Jackson and Marilda Sotomayor for their comments.     

Strategic Environmental Standards, Wage Incomes and the Location of Polluting Firms

The purpose of this paper is tostudy how the choice of environmental standardsby governments is affected by the existence ofwage incomes when firms locations areendogenous. In developed countries labor isunionized, which allows positive wage incomesto arise. Thus, each government has incentivesto persuade firms to locate in its countrysince social welfare depends on suchincomes. But, as pollution damages theenvironment, each government will only try toattract polluting firms to thecountry, to obtain the wage incomes, whenthe valuation of environmental damage showsthat it is low.     

Business Ethics in The Philippines

The plurality of languages and ethnicities, the geographic fragmentation, the predominant Roman Catholic religion, together with the still relatively short experience in nationhood account for a very peculiar understanding of "business ethics" in the Philippines. The rapid growth and liberalization of the economy, coupled with the inequitable distribution of wealth, the destruction of the environment and corruption are the main ethical concerns. Businesspersons and the academe endeavor to find creative solutions for these unique challenges.     

Frictions, Heterogeneity and Optimality in Mortgage Modeling

The purpose of this article is to provide a unified framework for incorporating frictions into a theoretical options-pricing model (OPM) for mortgages. This article presents formulation for a frictions-adjustable mortgage model that integrates borrower heterogeneity while simultaneously preserving prepayment and default financial decisions. Our model demonstrates the flexibility of the OPM by simulating separate and concurrent effects of three categories of frictions on the mortgage and mortgage components. Researchers can use our example formulation to determine the effects of specific borrower characteristics on mortgage values without destroying the options theoretic framework.     

THE ROLE OF FINANCIAL RELATIONSHIPS IN THE HISTORY OF AMERICAN CORPORATE FINANCE

The American corporate financing system, unlike that of most other countries, has not been organized around a set of “universal banks” that perform a variety of functions for their clients. Indeed, the distinguishing feature of American financial history is the number and variety of financial intermediaries, and their relationships with corporations (and one another). Besides commercial banks, there are investment banks, insurance companies, venture capitalists, commercial paper dealers, mutual funds, and many others. The economic role of such intermediaries is to reduce market frictions such as “asymmetric information” and “agency problems” that otherwise raise the cost of outside capital for U.S. companies. This article views the changing menu of such intermediaries and their networks as the driving force behind the evolution of American corporate finance. U.S. financial history is seen as a series of institutional and financial innovations designed in large part to work around costly restrictions on relationships–particularly, limits on the scale and scope of U.S. banks–that do not exist in most other countries. In terms of its success in reducing the information and control costs of corporate finance, the history of the American financial system includes periods of significant progress as well as major reversals. Three relatively successful periods– the early 19th-century in New England, the “incipient” universal banking of the 1920s, and modernday financial capitalism–are separated by periods of drastic reductions in the menu of financial relationships– particularly the Great Depression and its 20-year aftermath. Besides new financial claims like preferred stock and new intermediaries such as venture capitalists, another important innovation is new forms of cooperation among intermediaries– especially among banks, venture capitalists, trusts, pensions, and investment banks–that have enabled the U.S. financial system to provide some of the key advantages of universal banking systems. Some of the largest U.S. commercial banks today can be viewed as positioning themselves to play a central coordinating role in these new coalitions of intermediaries. In so doing, they may become the platform for a distinctively American universal banking system.     

Financial acumen, women speculators, and the Royal African company during the South Sea bubble

Price bubbles provide a unique opportunity to study the financial acumen of shareholders. We focus on the 1720 South Sea episode as experienced by the Royal African Company whose stock was more speculative than other joint stocks. During 1720 the company had a new large stock issue. This paper examines the financial acumen of those women who traded senior and engrafted stock across 1720. We find that depending on the pricing regime, these women at worst broke even on their activities or had positive speculative gains. Our findings are consistent with a growing literature on the positive link between gender, capital gains and financial markets.     

The Impact of Basel II on Lending to Small- and Medium-Sized Firms: A Regulatory Policy Assessment Based on Spanish Credit Register Data

The objective of this paper is to evaluate the impact on bank credit exposures to small- and medium-sized Spanish firms of the current proposal for reform of the 1988 Capital Accord using information from the Spanish Credit Register. Capital requirements for exposures to those firms, according to the various revisions of the proposed capital reform (from the January 2001 consultative document to the April 2003 one), are calculated to analyze whether the existing pattern of bank financing of small- and medium-sized firms might be altered. Finally, the incentives for individual banks to adopt the advanced internal ratings-based approach proposed by Basel II are evaluated.     

Farms’ technical inefficiencies in the presence of government programs*

We focus on determining the impacts of government programs on farms’ technical inefficiency levels. We use Kumbhakar's stochastic frontier model that accounts for both production risks and risk preferences. Our theoretical framework shows that decoupled government transfers are likely to increase (decrease) DARA (IARA) farmers’ production inefficiencies if variable inputs are risk decreasing. However, the impacts of decoupled payments cannot be anticipated if variable inputs are risk increasing. We use farm‐level data collected in Kansas to illustrate the model.