Nodal prices, capacity valuation and investments in natural gas markets - Overview and Analytical Framework

Especially in the short-term, prices in natural gas markets are not exclusively determined by overall supply and demand, but also by the availability of the transport infrastructure. If transportation capacity is scarce, prices may form in (local) residual markets and can differ regionally. If available, storages provide intertemporal arbitrage possibilities which also impact prices. Temporal and regional price differences, in turn, determine the value of storage and transport capacity if either one is scarce. This paper applies an analytical framework for a simple pipeline grid with a storage over two periods to illustrate the interdependencies between prices, scarce capacity and capacity value. The theoretically optimal transportation and storage tariffs are described analytically. The optimal pipeline investment size is shown to be related to marginal storage investment and a function of the discounted and aggregated cost of congestion over the lifetime's asset.Natural gas; Prices; Transport capacity; Storage; Investment

Individual Perceptions of the Criminal Justice System

This paper empirically examines perceptions of the criminal justice system held by young males using longitudinal survey data from the recent National Longitudinal Survey of Youth 1997 Cohort and the National Youth Survey. While beliefs about the probability of an arrest are positively correlated with local official arrest rates, they are largely idiosyncratic and unresponsive to information about the arrests of other random individuals and local neighborhood conditions. There is little support, therefore, for the `broken windows' theory of Wilson and Kelling (1982). Yet, perceptions do respond to changes in an individual's own criminal and arrest history. Young males who engage in crime but are not arrested revise their perceived probability of arrest downward, while those who are arrested revise their probability upwards. Beliefs respond similarly to changes in a sibling's criminal and arrest history. The perceived probability of arrest is then linked to subsequent criminal behavior. Cross-sectionally, youth with a lower perceived probability of arrest are significantly more likely to engage in crime during subsequent periods. Following an arrest, individuals commit less crime, consistent with deterrence theory and the fact that their perceived probability of arrest increases.

The Changing Role of Family Income and Ability in Determining Educational Achievement

This paper uses data from the 1979 and 1997 National Longitudinal Survey of Youth cohorts (NLSY79 and NLSY97) to estimate changes in the effects of ability and family income on educational attainment for youth in their late teens during the early 1980s and early 2000s. Cognitive ability plays an important role in determining educational outcomes for both NLSY cohorts, while family income plays little role in determining high school completion in either cohort. Most interestingly, we document a dramatic increase in the effects of family income on college attendance (particularly among the least able) from the NLSY79 to the NLSY97. Family income has also become a much more important determinant of college `quality' and hours/weeks worked during the academic year (the latter among the most able) in the NLSY97. Family income has little effect on college delay in either sample. To interpret our empirical findings on college attendance, we develop an educational choice model that incorporates both borrowing constraints and a `consumption' value of schooling - two of the most commonly invoked explanations for a positive family income-schooling relationship. Without borrowing constraints, the model cannot explain the rising effects of family income on college attendance in response to the sharply rising costs and returns to college experienced from the early 1980s to early 2000s: the incentives created by a `consumption' value of schooling imply that income should have become less important over time (or even negatively related to attendance). Instead, the data are more broadly consistent with the hypothesis that more youth are borrowing constrained today than were in the early 1980s.

The Effect of Education on Crime: Evidence from Prison Inmates, Arrests, and Self-Reports

We estimate the effect of high school graduation on participation in criminal activity accounting for endogeneity of schooling. We begin by analyzing the effect of high school graduation on incarceration using Census data. Instrumental variable estimates using changes in state compulsory attendance laws as an instrument for high school graduation uncover a significant reduction in incarceration for both blacks and whites. When estimating the impact of high school graduation only, OLS and IV estimators estimate different weighted sums of the impact of each schooling progression on the probability of incarceration. We clarify the relationship between OLS and IV estimates and show that the 'weights' placed on the impact of each schooling progression can explain differences in the estimates. Overall, the estimates suggest that completing high school reduces the probability of incarceration by about .76 percentage points for whites and 3.4 percentage points for blacks. We corroborate these findings using FBI data on arrests that distinguish among different types of crimes. The biggest impacts of graduation are associated with murder, assault, and motor vehicle theft. We also examine the effect of drop out on self-reported crime in the NLSY and find that our estimates for imprisonment and arrest are caused by changes in criminal behavior and not educational differences in the probability of arrest or incarceration conditional on crime. We estimate that the externality of education is about 14-26% of the private return to schooling, suggesting that a significant part of the social return to education comes in the form of externalities from crime reduction.

Credit Constraints in Education

We review studies of the impact of credit constraints on the accumulation of human capital. Evidence suggests that credit constraints are increasingly important for schooling and other aspects of households' behavior. We highlight the importance of early childhood investments, since their response largely determines the impact of credit constraints on the overall lifetime acquisition of human capital. We also review the intergenerational literature and examine the macroeconomic impacts of credit constraints on social mobility and the income distribution. A common limitation across all areas of the human capital literature is the imposition of ad hoc constraints on credit. We propose a more careful treatment of the structure of government student loan programs as well as the incentive problems underlying private credit. We show that endogenizing constraints on credit for human capital helps explain observed borrowing, schooling, and default patterns and offers new insights about the design of government policy.Human Capital, Incentive Problems, Government Loans, Early Investments, Social Mobility