Foreign banks in Japan: A study of a Japanese deregulation process

The deregulation of foreign banks in Japan, although corresponding in broad outline to world-wide trends, has diverged substantially in many particulars from patterns seen elsewhere. It has tended to be excruciatingly slow and piecemeal and to have been of minimal benefit to foreign banks. A review of this process leads to the conclusion that these characteristics result from organisational and political-bureaucratic factors inherent to the Japanese style of government which is, in turn, partially a reflection of Japanese culture. Although these non-economic factors have influenced the specific pattern of change, its overall direction appears to have been consistent with the broader national interest.The authors wish to acknowledge financial support from the Social Science and Humanities Research Council of Canada, the Florsheimer Center for Policy Studies, and the Krueger Center for Financial Research.     

Ambiguity aversion and the absence of wage indexation

This paper analyzes optimal wage contracting assuming agents are not subjective expected utility maximizers but are, instead, ambiguity (or uncertainty) averse decision makers who maximize Choquet expected utility. We show that such agents will choose not to include any indexation coverage in their wage contracts even when inflation is uncertain, unless the perceived inflation uncertainty is high enough. Significantly, the exercise does not presume any exogenous costs (e.g., transactions costs) of including indexation links.     

On multiple equilibria and the rational expectations hypothesis?

Summary. This paper analyzes through a simple two-period model the fact that, if some agents hold inside money intertemporally, the second-period “normalization” matters. Thus, there are several equilibria of the second-period economy, indexed by the level of inflation. A concept of equilibrium acknowledging this fact, and requiring that agents put some weight on any of the possible second-period equilibrium price vectors is developed. Such an equilibrium is shown to exist, and is illustrated by an example.     

Diversification, convex preferences and non-empty core in the Choquet expected utility model

Summary. We show, in the Choquet expected utility model, that preference for diversification, that is, convex preferences, is equivalent to a concave utility index and a convex capacity. We then introduce a weaker notion of diversification, namely “sure diversification.” We show that this implies that the core of the capacity is non-empty. The converse holds under concavity of the utility index, which is itself equivalent to the notion of comonotone diversification, that we introduce. In an Anscombe-Aumann setting, preference for diversification is equivalent to convexity of the capacity and preference for sure diversification is equivalent to non-empty core. In the expected utility model, all these notions of diversification are equivalent and are represented by the concavity of the utility index. Received: July 27, 1999; revised version: November 7, 2000     

Measuring Inequalities without Linearity in Envy: Choquet Integrals for Symmetric Capacities

The (generalized) Gini indices rely on the social welfare function of a decision maker who behaves in accordance with Yaari's model, with a function f that transforms frequencies. This SWF can also be represented as the weighted sum of the welfare of all the possible coalitions in the society, where the welfare of a coalition is defined as the income of the worst-off member of that coalition. We provide a set of axioms (Ak) and prove that the three following statements are equivalent: (i) the decision maker respects (Ak), (ii) f is a polynomial of degree k, (iii) the weight of all coalitions with more than k members is equal to zero. Journal of Economic Literature Classification Number: D63.     

On multiple equilibria and the rational expectations hypothesis

Summary This paper analyzes through a simple two-period model the fact that, if some agents hold inside money intertemporally, the second-period normalization matters. Thus, there are several equilibria of the second-period economy, indexed by the level of inflation. A concept of equilibrium acknowledging this fact, and requiring that agents put some weight on any of the possible second-period equilibrium price vectors is developed. Such an equilibrium is shown to exist, and is illustrated by an example.This a revised version of chapter three of my Ph.D. dissertation. I would like to thank David Cass, Atsushi Kajii, George Mailath and Shinichi Suda for helpful discussions and comments. Thanks are also due to Jean-Michel Grandmont who pointed out mistakes in a previous version. All remaining mistakes are of course my own. Financial support from a CARESS scholarship at the University of Pennsylvania is gratefully acknowledged.     

DECISION THEORY UNDER AMBIGUITY

Abstract We review recent advances in the field of decision making under uncertainty or ambiguity. We start with a presentation of the general approach to a decision problem under uncertainty, as well as the ‘standard’ Bayesian treatment and issues with this treatment. We present more general approaches (Choquet expected utility, maximin expected utility, smooth ambiguity and so forth) that have been developed in the literature under the name of models of ambiguity sensitive preferences. We draw a distinction between fully subjective models and models incorporating explicitly some information. We review definitions and characterizations of ambiguity aversion in these models. We mention the challenges posed by some of the models presented. We end with a review of part of the experimental literature and applications of these models to economic settings.     

Multidimensional generalized Gini indices

Summary. The axioms that characterize the generalized Gini social evaluation orderings for one-dimensional distributions are extended to the multidimensional attributes case. A social evaluation ordering is shown to have a two-stage aggregation representation if these axioms and a separability assumption are satisfied. In the first stage, the distributions of each attribute are aggregated using generalized Gini social evaluation functions. The functional form of the second-stage aggregator depends on the number of attributes and on which version of a comonotonic additivity axiom is used. The implications of these results for the corresponding multidimensional indices of relative and absolute inequality are also considered.Received: 20 August 2003, Revised: 26 May 2004, JEL Classification Numbers: D63. Correspondence to: John A. WeymarkWe are grateful to our referee for his or her comments.     

Cost-effectiveness of combination daclatasvir-sofosbuvir for treatment of genotype 3 chronic hepatitis C infection in the United States

Background: A phase III trial evaluated the efficacy and safety of Daklinza (daclatasvir or DCV) in combination with sofosbuvir (SOF) for treatment of genotype (GT) 3 hepatitis C virus (HCV) patients.

Aim: This study evaluated the cost-effectiveness of DCV?+?SOF vs SOF in combination with ribavirin (RBV) over a 20-year time horizon from the perspective of a United States (US) payer.

Methods: A published Markov model was adapted to reflect US demographic characteristics, treatment patterns, costs of drug acquisition, monitoring, disease and adverse event management, and mortality risks. Clinical inputs came from the ALLY-3 and VALENCE trials. The primary outcome was the incremental cost-utility ratio. Life-years, incidence of complications, number of patients achieving sustained virological response (SVR), and the total cost per SVR were secondary outcomes. Costs (2014 USD) and quality-adjusted life years (QALYs) were discounted at 3% per year. Deterministic, probabilistic, and scenario sensitivity analyses were conducted.

Results: DCV?+?SOF was associated with lower costs and better effectiveness than SOF?+?RBV in the base case and in almost all scenarios (i.e. treatment-experienced, non-cirrhotic, time horizons of 5, 10, and 80 years). DCV?+?SOF was less costly, but also slightly less effective than SOF?+?RBV in the cirrhotic and treatment-naïve population scenarios. Results were sensitive to variations in the probability of achieving SVR for both treatment arms. DCV?+?SOF costs less than $50,000 per QALY gained in 79% of all probabilistic iterations compared with SOF?+?RBV.

Conclusion: DCV?+?SOF is a dominant option compared with SOF?+?RBV in the US for the overall GT 3 HCV patient population.