Risk Aversion and Income Tax Enforcement

This paper characterizes optimal income tax and audit schemes in the presence of costly enforcement when the agent is risk averse and not necessarily risk neutral. It is shown that the results under risk-neutrality (Chander and Wilde (1998)) largely hold under risk aversion. We first show that in an optimal scheme the tax evasion decision of the agent is equivalent to risking his entire income against a possible gain in terms of lower tax payment. We then introduce a measure of aversion to such large risks. In contrast, the Arrow-Pratt coefficients of risk aversion measure aversion to small risks only. We show that the optimal tax function is non-decreasing and concave if the agent’s aversion to large risks, as defined in terms of our measure, is decreasing with income. The optimal audit function is non-increasing and the audits may be random or deterministic.expected utility, risk aversion, principal-agent, adverse selection

The Gamma-Core and Coalition Formation

This paper reinterprets the gamma-core (Chander and Tulkens (1995, 1997)) and justifies it as well as its prediction that the efficient coalition structure is stable in terms of the coalition formation theory. It is assumed that coalitions can freely merge or break apart, are farsighted (that is, it is the final and not the immediate payoffs that matter to the coalitions) and a coalition may deviate if and only if it stands to gain from it. It is then shown that subsequent to a deviation by a coalition, the nonmembers will have incentives to break apart into singletons, as is assumed in the definition of the gamma-characteristic function, and that the grand coalition is the only stable coalition structure.strategic games, coalition formation, farsighted, core, characteristic function

Cores of games with positive externalities

This paper introduces a core concept, called the γ-core, in the primitive framework of a strategic game. For a certain class of strategic games, it is a weaker concept than the strong Nash equilibrium, but in general stronger than the conventional α- and β- cores. We argue that the coalition formation process is an infinitely repeated game and show that the grand coalition forms if the γ-core is nonempty. This is a weaker sufficient condition than the previous such condition (Maskin (2003, Theorem 4)). As an application of this result, it is shown that the γ- core of an oligopolistic market is nonempty and thus the grand coalition forms.positive externalities, strategic game, core, repeated game, coalition formation

Optical Absorption Characteristics of Silicon Nanowires for Photovoltaic Applications

Solar cells have generated a lot of interest as a potential source of clean renewable energy for the future. However a big bottleneck in wide scale deployment of these energy sources remain the low efficiency of these conversion devices. Recently the use of nanostructures and the strategy of quantum confinement have been as a general approach towards better charge carrier generation and capture. In this article we have presented calculations on the optical characteristics of nanowires made out of Silicon. Our calculations show these nanowires form excellent optoelectronic materials and may yield efficient photovoltaic devices

Green consumerism and collective action

We analyze the effect of collective action by green/environmentally aware consumers on ambient environmental quality and market equilibrium. We consider a model with two types of consumers who differ in their willingness-to-pay for a good available in two different environmental qualities, and two competing firms: one selling the good of high environmental quality and the other of low environmental quality. We show that collective action by green consumers reduces competition and leads to higher prices for the good of both qualities. Though it improves the ambient environmental quality, it may reduce the welfare of both types of consumers.green consumers, collective action, environmental quality, differentiated duopoly, firm profitability

Cooperation, Stability and Self-Enforcement in International Environmental Agreements: A Conceptual Discussion

In essence, any international environmental agreement (IEA) implies cooperation of a form or another. The paper seeks for logical foundations of this. It first deals with how the need for cooperation derives from the public good aspect of the externalities involved, as well as with where the source of cooperation lies in cooperative game theory. In either case, the quest for efficiency is claimed to be at the root of cooperation. Next, cooperation is considered from the point of view of stability. After recalling the two competing concepts of stability in use in the IEA literature, new insights on the nature of the gamma core in general are given as well as of the Chander-Tulkens solution within the gamma core. Free riding is also evaluated in relation with the alternative forms of stability under scrutiny. Finally, it is asked whether with the often mentioned virtue of “self enforcement” any conceptual gain is achieved, different from what is meant by efficiency and stability. A skeptical answer is offered, as a reply to Barrett’s (2003) attempt at giving the notion a specific content.International Environmental Agreements, Cooperation, Stability, Self-enforcement

Automatic resynchronisation of synchronous machines

Imperial Users onl

Incentives and a Process Converging to the Core of a Public Goods Economy

The paper considers economies involving one public good, one private good, and constant returns to scale. It is shown that the process proposed earlier in Chander (1983, 1987a, and 1987b) always converges to an allocation which is in the core of the economy. This is then interpreted as an incentive property of the process and it is shown that there exists no process which always converges to the core and in which truth-telling constitutes a dominance equilibrium of the 'local incentive game'

Workers’ Participations in the Management of H.P. State Electricity Board

Participative management recognizes the desire of the workers for a say, an involvement and control over and understanding of the decisions which affects their lives. Workers’ participation in management which meet the aspirations of the workmen and have recently emerged are respectively the whitely type councils, profit-sharing plans and co-partnership, and worker-director schemes, sharing of information with, and consulting, workers to sharing the right of decision-making on issues of interest to the working class. Whatever may be the form of control there is inevitably some flow of power and authority from management to workers

Comparing Stellar Populations of Galaxies across the Hubble Sequence: Reduction of PISCES Near-Infrared Images

To better understand the properties of high redshift galaxies and improve models of galaxy formation, we are investigating color radial profiles to study the stellar age, dust and metallicity distribution of galaxies of varying lumi-nosities and morphological types. Current data obtained in the optical and UV have shown that early-type galaxies have a flat color profile, or are bluer at larger radii, while late-type spirals are redder with increasing radius. These trends are believed to be linked with stellar population ages or dust. To break the age-dust degeneracy as well as to avoid the metallicity dependence, we have obtained near-infrared images of Nearby Field Galaxy Survey (NFGS) galax-ies taken with the PISCES Wide-field Infrared Camera on the 90-inch Bok Telescope. Combined with the optical and UV data, these new, near-infrared images will help better constrain these parameters and determine the ages of the stellar components of the galaxies. We discuss the method used to process and reduce the data and present the radial profile of the surface brightness and color of one particular galaxy in the sample, UGC 439