Measuring market response to regulation of the cable TV industry

During the 1988–1990 period, the cable television industry was subject to a number of regulatory events. These centered on possible reregulation of rates for basic service and reduction of entry barriers for potential competitors. Using the event study methodology on a portfolio of cable firms, we find evidence that news of no reregulation caused significant positive abnormal returns. News of reregulation caused insignificant negative abnormal returns. These findings provide some support for the traditional consumer protection theory of regulation. News related to entry barriers generally had no significant effect on returns, which suggests that elements of natural monopoly may exist in the industry.     

Inter-enterprise arrears in economies in transition

In the context of economies in transition, the paper argues that an excessive liquidity squeeze could throw the economy into a persistent state of low economic activity. In such bad equilibrium, enterprise transactions become largely demonetized, with a chain of arrears, a form of involuntary credit, spreading over the entire system. The empirical analysis of the Romanian experience seems to support the view advanced in the paper.     

Contrast enhancement of the gastrointestinal tract on MR images using intravenous gadolinium-DTPA

Gadopentetate dimeglumine was administered intravenously to 16 patients undergoing abdominal magnetic resonance (MR) imaging. T1-weighted and fat-suppressed T1-weighted images were acquired before and after intravenous administration of 0.1 mmol/kg gadopentetate dimeglumine. The stomach, small bowel, and colon were analyzed regarding the presence and relative intensity of contrast enhancement. Diffuse enhancement of the gastrointestinal tract wall was observed in all patients following contrast material administration. Such enhancement was most conspicuous on fat-suppressed T1-weighted images. Quantitative measurements indicated that the wall of the gastrointestinal tract enhanced approximately 100% with gadopentetate dimeglumine. This study demonstrates that enhancement of the normal gastrointestinal tract occurs routinely when intravenous gadopentetate dimeglumine is administered, and such enhancement should not be considered indicative of gastrointestinal pathology. Furthermore, it suggests the potential utility for using intravenous rather than orally administered contrast agents to provide enhancement of the gastrointestinal tract on MR images.     

The dynamics of some duopoly games involving the Market Share and Nichol strategies

The paper analyses the dynamics of some duopoly output games involving the Cournot, Market-Share and Nichol strategies. The model assumes linear price and cost functions and supposes that outputs are adjusted instantaneously at discrete time intervals. For all games considered, equilibrium is either reached after a finite number of moves or a stable approach to equilibrium occurs as t → ∞. In fact, apart from a few uninteresting cases, arising from the oversimplified form of the Market-Share strategy, all equilibrium points lie on specified parts of the firms' Cournot loci.     

DISTRIBUTION OF WEALTH IN THE UNITED KINGDOM: EFFECT OF INCLUDING PENSION RIGHTS,AND ANALYSIS BY AGE-GROUP*

This article on the distribution of wealth among individuals in the United Kingdom presents recent work on the effects of including pension rights and the significance of sex, age and marital status. It describes the rationale for including the accrued rights in occupational and State pension schemes (funded or unfunded) and the methods of estimation used. For funded schemes the rights are valued as the accrued liability of the schemes to their members, and for unfunded schemes similar liabilities are hypothecated; these estimates of the value of accrued pension rights involve assumptions about future earnings and interest rates. The trend in average marketable wealth with age is upwards until advanced years when it slows down or slightly reverses. Adding occupational pension rights only slightly raises the trend for females but has a bigger effect for males. Adding State pension rights raises these upward trends until the age of 60 after which there is a decline. For marketable wealth on the average males are wealthier than females but less wealthy if single, divorced or widowed. Adding occupational pension rights improves the relative position of males; adding State pension rights cancels this out. The effect of marital status rises with both age and sex and therefore a detailed three-way analysis is made. For females widows are on average the wealthiest; for young males the married; for older males the single. Using Theil's coefficient of entropy for comparing the inequality of wealth, the addition of pension rights reduces inequality by two-thirds. Age accounts for only 6 percent of inequality for marketable wealth but for 31 percent if pension rights are included.     

An algebraic theory of multi-product decisions

Summary. We exploit the existence of matrix group symmetries on a production possibility set to identify group symmetries on the profit function. The groups are isomorphic, and provide a pre-ordering on firm preferences over prices. Together with additional structure on the technology, symmetries generate comparative statics on price responses. Linear and other invariances place bounds on firm choice vectors. Reflection group asymmetries on the feasible choice set also support welfare rankings over prices. The methods are adapted to study consumer decisions.Received: 12 August 2002, Revised: 30 January 2004, JEL Classification Numbers: D11, D21, C60, L23. Correspondence to: David A. Hennessy     

Consistency and optimality in a dynamic game of pollution control II: Monopoly

This paper continues a line of research begun in Batabyal (1995a). I model the interaction between a regulator and a monopolistic, polluting firm as a Stackelberg differential game in which the regulator leads. The firm creates pollution, which results in a stock externality. I analyze the intertemporal effects of alternate pollution control measures. The principal issue here concerns the dynamic inconsistency of the optimal solution. Inter alia, I compare the steady state levels of pollution under optimal and under dynamically consistent policies.     

Economic Potential of Biomass Based Fuels for Greenhouse Gas Emission Mitigation

Use of biofuels diminishes fossil fuelcombustion thereby also reducing net greenhousegas emissions. However, subsidies are neededto make agricultural biofuel productioneconomically feasible. To explore the economicpotential of biofuels in a greenhouse gasmitigation market, we incorporate data onproduction and biofuel processing for thedesignated energy crops switchgrass, hybridpoplar, and willow in an U.S. AgriculturalSector Model along with data on traditionalcrop-livestock production and processing, andafforestation of cropland. Net emissioncoefficients on all included agriculturalpractices are estimated through crop growthsimulation models or taken from the literature. Potential emission mitigation policies ormarkets are simulated via hypothetical carbonprices. At each carbon price level, theAgricultural Sector Model computes the newmarket equilibrium, revealing agriculturalcommodity prices, regionally specificproduction, input use, and welfare levels,environmental impacts, and adoption ofalternative management practices such asbiofuel production. Results indicate no rolefor biofuels below carbon prices of $40 perton of carbon equivalent. At these incentivelevels, emission reductions via reduced soiltillage and afforestation are more costefficient. For carbon prices above $70,biofuels dominate all other agriculturalmitigation strategies.     

Industrial revolution and mortality revolution: Two of a kind?

In little more than a century life expectancy has doubled in most parts of the world. Neither facts nor theory support the view that this Mortality Revolution is due to the Industrial Revolution and the era of rapid economic growth that ensued. Rather, both revolutions mark the onset of accelerated and sustained technological change in their respective areas. They occur largely independently of each other, the later occurrence of the Mortality Revolution being due to the later development of biomedical vis-a-vis physical knowledge. Comparative study of the two should prove fruitful. Although entrepreneurship is important in each, there appear to be differences in the underlying motivations and the role of private property and other institutions. Links between technological change, on the one hand, and scale of operation, capital inputs, and education, on the other, also offer promising possibilities for comparative study.The author is grateful to Donna Hokoda Ebata and Christine M. Schaeffer for excellent assistance, the University of Southern California for financial support, and to Eileen M. Crimmins, Samuel H. Preston, Morton O. Schapiro, Roger S. Schofield, and two referees for helpful comments.