The underlying event in jet and minimum bias events at the Tevatron

We describe a study of the underlying event in jet and minimum bias events using data from the CDF detector. The underlying event contribution to the jet energy has been calculated in jet events and compared to the results of two Monte Carlo programs: Herwig and Pythia. The analysis has been carried out at two different center of mass energies: $\sqrt{s}=$1800 and 630 GeV. For most observables, good agreement is obtained with at least one of the Monte Carlo programs. Neither program describes all features of the data.Comment: 4 pages, 4 figures (in eps) talk given at XXXI International Symposium on Multiparticle Dynamics, Sep. 1-7, 2001, Datong China URL http://ismd31.ccnu.edu.cn

Equality is Not Necessarily Just: Toward a Procedural and Relational View of Evironmental Justice

This paper is the latest in a series of articles written to conceptualize an alternative to the distributive paradigm espoused by the environmental justice movement. It is clear that early studies such as the "Toxic Waste and Race in the United States: A National Report on the Racial and Socio-Economic Characteristics of Communities with Hazardous Waste Sites" prepared by the Commission for Racial Justice of the United Church of Christ exposed the potential our present model of environmental regulation has to create distributional inequities and forced policymakers to identify how the burdens as well as the benefits of environmental protection are spread among groups of persons.It is also clear to me that distributive theories of environmental justice are inadequate to justify a more just environmental policy or support the aims of the environmental justice movement. I share with Iris Marion Young a view that the distributive paradigm's implicit assumption that social judgments are about what individual person have, how much they have, and how that amount compares with what other persons have and the belief that this focus on possession is limiting. Distributive theories of justice tend to preclude thinking about what people are doing according to what institutionalized rules, how their doings and havings are structured by institutionalized relations that constitute their positions, and how the combined effects of their doings has recursive effects on their lives. What I attempt to do in this paper is to shift the focus of the discussion away from the distribution and on the decision-making structures and procedures which determine what there is to distribute, how it gets distributed, who distributes and what the distributive outcome is. To paraphrase Ms. Young, environmental injustice occurs not simply because some persons have cleaner air and water than others' environmental injustice derives as much from the corporate and legal structures and procedures that give some persons the power to make decisions that affect millions of other people

Referrals

Specialization requires that workers deal with some valuable opportunities themselves and refer other, possibly unverifiable, opportunities to other workers. How do markets and organizations ensure the matching of opportunities with talent in the presence of informational asymmetries about their value? The cost of providing incentives for effort in this context is that they increase the risk of the agent appropriating an opportunity she should refer upstream. Thus spot markets are severely limited in their ability to support referrals, as they involve very powerful effort incentives on those opportunities kept by the referring agents. We show that partnerships, in which agents agree to share opportunities and the income from the opportunities, appear endogenously as a solution to this problem. Partnership contracts support better communication rules at the expense of biasing effort provision away from first best for all activities. The structure of the contract depends both on the frequency of communications and on the interaction between the relative skill of the agents and the direction of the referral flow.

The Demand for Coordination

This paper endogenizes coordination problems in organizations by allowing for both ex ante coordination of activities, using rules and task guidelines, and ex post coordination, using communication and broad job assignments. It shows that: (i) Task specialization and the division of labor is mainly limited by employee discretion, rather than by the importance of coordination. In particular, specialization is often non-monotonic in the importance of coordination. (ii) Organizations exhibit increasing returns to ex post coordination. This rationalizes discrete `shifts' in organizational design from very rigid and specialized task assignments, to very flexible organizations characterized by extensive task bundling, intensive horizontal communication and substantial employee discretion. (iii) Broad task assignments and intensive horizontal communication are complementary. Hence, lower communication costs often result in less specialization.

Cash-Flow Risk, Discount Risk, and the Value Premium

A habit persistence, general equilibrium model with multiple assets matches both the time series properties of the market portfolio and the cross-sectional predictability of returns on price sorted portfolios, the value premium. Consistent with empirical evidence, the model shows that (a) value stocks are those with higher cash-flow risk; (b) the size of the value premium is larger in %u201Cbad times,%u201D due to time variation in risk preferences; (c) the unconditional CAPM fails, because of general equilibrium restrictions on the market portfolio. The dynamic nature of the value premium rationalizes why the conditional CAPM and a Fama and French (1993) HML factor outperform the unconditional CAPM.

Conditional Betas

Empirical evidence shows that conditional market betas vary substantially over time. Yet, little is known about the source of this variation, either theoretically or empirically. Within a general equilibrium model with multiple assets and a time varying aggregate equity premium, we show that conditional betas depend on (a) the level of the aggregate premium itself; (b) the level of the firm's expected dividend growth; and (c) the firm's fundamental risk, that is, the one pertaining to the covariation of the firm's cash-flows with the aggregate economy. Especially when fundamental risk (c) is strong, the model predicts that market betas should display a large time variation, that their cross-sectional dispersion should be negatively related to the aggregate premium, and that investments in physical capital should be positively related to changes in betas. These predictions find considerable support in the data.

Labor Income and Predictable Stock Returns

We propose and test a novel economic mechanism that generates stock return predictability on both the time series and the cross section. In our model, investors' income has two sources, wages and dividends, that grow stochastically over time. As a consequence, the fraction of total income produced by wages changes over time de-pending on economic conditions. We show that as this fraction fluctuates, the risk premium that investors require to hold stocks varies as well. We test the main implications of the model and find substantial support for it. A regression of stock returns on lagged values of the labor income to consumption ratio produces statistically significant coefficients and adjusted R2 's that are larger than those generated when using the dividend price ratio. Tests of the cross sectional implication find considerable improvements on the performance of both the conditional CAPM and CCAPM when compared to their unconditional counterparts.

Brugada Syndrome: Presentation and Management of the Atypical Patient in the Emergent Setting

Introduction: Brugada syndrome is a genetic disorder of the heart’s electrical system that increases a patient’s risk of sudden cardiac death. It is a syndrome most prevalent in Southeast Asians and is found 36 times more commonly in Asians than in Hispanics.Case Report: We report and discuss a case of a 68-year-old Hispanic male who presented with clinical and electrocardiogram abnormalities consistent with Brugada syndrome.Discussion: The patient’s age and ethnicity represents an atypical presentation of this rare syndrome and the lack of reported studies in the literature pertaining to these demographics reflect this.Conclusion: Further studies and characterizations are necessary as manifestations continue to be unearthed. As such, Brugada Syndrome should be considered in the differential diagnosis for a myriad of patient populations