Intertemporal regulatory tasks and responsibilities for greenhouse gas reductions

Jurisdictions are in the process of establishing regulatory systems to control greenhouse gas emissions. Short‐term and sometimes long‐term emissions reduction goals are established, as California does for 2020 and 2050, but little attention has yet been focused on annual emissions targets for the intervening years. We develop recommendations for how these annual targets—which we collectively term a “compliance pathway”—can be set, as well as what flexibility sources should have to adjust in light of cost uncertainties. Environmental effectiveness, efficiency, equity, adaptability, and encouraging global participation are appropriate criteria by which these intertemporal policy alternatives should be judged. Limited but useful knowledge about costs leads us to recommend a compliance pathway characterized by increasing incremental reductions along it. This can be approximated by discrete linear segments, which may fit better with global negotiations. Although the above conclusion applies to any long‐term GHG regulatory program, many jurisdictions will rely heavily on a cap‐and‐trade system, and the same pathway recommendation applies to its time schedule of allowances. Furthermore, borrowing constraints in cap‐and‐trade systems can impose substantial unnecessary costs. To avoid most of these costs, we recommend that sources be allowed early use of limited percentages of allowances intended for future years. We also find that a three‐year compliance period can have substantial benefit over a one‐year period. © 2010 by the Association for Public Policy Analysis and Management.     

Radiological determination of the cranial index of present-day Ghanaians

The cranial index (CI) of Ghanaians is currently unknown. The aim of this study was to measure the CI in a population of Ghanaians in order to classify them against pre-determined CI categories. A systematic random sampling method was used to select 300 normal computed tomography (CT) head scans of adult Ghanaians from the largest hospital in Ghana. All patients were deemed to have a normal cranial image configuration based on the radiological report. The biparietal diameter (BPD, width) and the occipitofrontal diameter (OFD, length) were measured on transaxial CT images using a workstation with a calibrated measurement calliper tool. The CI ratio was calculated as the BPD multiplied by 100 and divided by the OFD. Mean, standard deviation (SD) and range were calculated for BPD, OFD and CI. Differences in measurements between demographic groups were compared using an unpaired t-test, with test α set at 0.05. Of the population of Ghanaians included in this study, 165 (55%) were male and 135 (45%) were female. The mean CI was 77.3 ± 3.6 in males and 79.0 ± 3.3 in females, placing both genders in the mesocephalic category. However, the difference between males and females was found to be statistically significant (P = 0.02). The study indicated that most Ghanaian adults belong to the mesocephalic category of CI. Females also had a higher CI, which could be used to differentiate gender groups. This information can be useful for forensic medicine, plastic surgeries for clinical and research purpose.

Key points

• This study found the mean CI of adult Ghanaians to be 78.0 ± 13.0.
• This indicates that most Ghanaian adults belong to the mesocephalic category of CI.
• Females had a higher CI, which could be used to differentiate gender groups.
• To the best of our knowledge, this is the first study which assessed CI of Ghanaians using CT scan.

     

A comparative analysis of jails in the United States and Bangladesh

There are comparative analyses in the current criminal justice literature but few focus on Asian cultures and even fewer compare Muslim countries with the United States. While comprehensive comparative studies are needed, preliminary studies that correlate the functional similarities and differences are also necessary. Hence, the purpose of this paper is to conduct a comparative analysis of the jails in Bangladesh and the United States. The data for this study are taken directly from Bangladesh population summary reports and a matched sample of American Jails from the Bureau of Justice Statistics Jail Census (1990). The comparative data are key functional measures from each country and are used as the basis for classifying the jails into two groups. The findings indicate that there are key differentiating variables (crowding and population turnover) that allow one to classify the jails in the two nations. Although this study provides clear evidence for the differences between American and Bangladeshi jails, further in‐depth analyses should follow.     

Is Information Enough? The Effect of Information about Education Tax Benefits on Student Outcomes

There is increasing evidence that tax benefits for college do not affect college enrollment. This may be because prospective students do not know about tax benefits for college or because the design of tax benefits is not conducive to affecting educational outcomes. We focus on changing awareness of tax benefits by providing information to students or prospective students. We sent e‐mails and letters to students that described tax benefits for college, and we tracked college outcomes. For all three of our samples—rising high school seniors, already enrolled students, and students who had previously applied to college but were not currently enrolled—information about tax benefits for college did not affect enrollment or reenrollment. We test whether effects vary according to information frames and found that no treatment arms changed student outcomes. We conclude that awareness is not the primary reason that tax benefits for college do not affect enrollment.     

School Starting Age and Cognitive Development

We present evidence of a positive relationship between school starting age and children's cognitive development from ages 6 to 18 using a fuzzy regression discontinuity design and large‐scale population‐level birth and school data from the state of Florida. We estimate effects of being old for grade (being born in September vs. August) that are remarkably stable—always around 0.2 SD difference in test scores—across a wide range of heterogeneous groups, based on maternal education, poverty at birth, race/ethnicity, birth weight, gestational age, and school quality. While the September‐August difference in kindergarten readiness is dramatically different by subgroup, by the time students take their first exams, the heterogeneity in estimated effects on test scores effectively disappears. We do, however, find significant heterogeneity in other outcome measures such as disability status and middle and high school course selections. We also document substantial variation in compensatory behaviors targeted towards young‐for‐grade children. While the more affluent families tend to redshirt their children, young‐for‐grade children from less affluent families are more likely to be retained in grades prior to testing. School district practices regarding retention and redshirting are correlated with improved outcomes for the groups less likely to use those remediation approaches (i.e., retention in the case of more affluent families and redshirting in the case of less affluent families.) Finally, we find that very few school policies or practices mitigate the test score advantage of September‐born children.