Simulation of the Colombian Firm Energy Market

We present a simulation analysis of the proposed Colombian firm energy market. The main purpose of the simulation is to assess the risk to suppliers of participation in the market. We also are able to consider variations in the market design, and assess the impact of alternative auction parameters. Three simulation models are developed and analyzed. The first model (Model 1) uses historical price data from October 1995 through May 2006 to assess the performance risk of hypothetical thermal and hydro generating units. The second model (Model 2) uses historical price and operating data to assess performance risk of the actual generating units in Colombia over the same period. This analysis allows us to assess company risk. The third model (Model 3) differs from the other models in that it explicitly models the firm energy auction and investments going forward. Thus, the model is able to assess how the distribution of firm energy purchases differs from the firm energy target, and how this distribution depends on the firm energy demand curve. Model 3 also studies the investment decisions of suppliers, the impact of lumpy investments, and the impact of a higher scarcity price. Taken together, the simulation results demonstrate the risk reducing benefits of the firm energy market. Provided there is competitive new entry in response to load growth, the firm energy market should work well at coordinating investment in new supply, while minimizing supplier and consumer risks.Auctions

Complementary Algorithms For Tableaux

We study four operations defined on pairs of tableaux. Algorithms for the first three involve the familiar procedures of jeu de taquin, row insertion, and column insertion. The fourth operation, hopscotch, is new, although specialised versions have appeared previously. Like the other three operations, this new operation may be computed with a set of local rules in a growth diagram, and it preserves Knuth equivalence class. Each of these four operations gives rise to an a priori distinct theory of dual equivalence. We show that these four theories coincide. The four operations are linked via the involutive tableau operations of complementation and conjugation.Comment: 29 pages, 52 .eps files for figures, JCTA, to appea

Incarceration and the Economic Fortunes of Urban Neighborhoods

New research has identified the consequences of high rates of incarceration on neighborhood crime rates, but few studies have looked beyond crime to examine the collateral effects of incarceration on the social and economic well being of the neighborhoods themselves and their residents. We assess two specific indicia of neighborhood economic well-being, household income and human capital, dimensions that are robust predictors of elevated crime, enforcement and incarceration rates. We decompose incarceration effects by neighborhood racial composition and socio-economic conditions to account for structural disadvantages in labor force and access to wealth that flow from persistent patterns of residential segregation. We use panel methods to examine the effects on incarceration on New York City census tracts over an 11 year period from 1985-1996, a period which saw crime rates rise and fall sharply, and when incarceration rates increased and remained high in concentrated areas throughout the city. We examine whether persistently high incarceration rates erode human capital and depress median household incomes, further intensifying incarceration risks and threatening to create conditions where incarceration and economic disadvantage become endogenous features of certain neighborhoods. We find distinct but overlapping effects for prisons and jails, suggesting that these are parallel processes produced by loosely coupled law enforcement priorities. Incarceration effects are greater for household income than human capital, suggesting a complex relationship between persistent poverty, residential segregation, and incarceration that reinforces a classic poverty trap. Household incomes are lower over time in neighborhoods with higher proportions of African American population, even after controlling for the effects of race on incarceration, but we find no similar effects for Hispanic populations. Spatially targeted policies such as microinvestment and housing development may be needed offset the local embeddedness of poverty and disrupt its connections to incarceration and crime, while education policy and transitional labor market networking can strengthen local human capital

The Decline of the Juvenile Death Penalty: Scientific Evidence of Evolving Norms

In 2003, the Missouri Supreme Court set aside the death sentence of Christopher Simmons, who was 17 when he was arrested for the murder of Shirley Crook. The Simmons court held that the evolving standards of decency embodied in the Eighth Amendment\u27s prohibition of cruel and unusual punishments barred execution of persons who committed capital crimes before their 18th birthday. This decision was based in part on the emerging legislative consensus in the states opposing execution of juvenile offenders and the infrequency with which the death penalty is imposed on juvenile offenders. The State sought a writ of certiorari, and the case is now before the U.S. Supreme Court. This article presents results of analyses of empirical data on the use of the death penalty for adolescent homicide offenders in state courts in the U.S. since 1990. The data show that, since 1994, when death sentences for juvenile offenders peaked, juvenile death sentences have declined significantly. In particular, the decline in juvenile death sentences since 1999 is statistically significant after controlling for the murder rate, the juvenile homicide arrest rate, and the rate of adult death sentences. This downward trend in juvenile death sentences signals that there is an evolving standard in state trial courts opposing the imposition of death sentences on minors who commit capital offenses