Teacher Mobility, School Segregation, and Pay-Based Policies to Level the Playing Field

Analyzes the effectiveness of using salary differentials to help schools serving disadvantaged students attract and retain highly qualified teachers. Examines teachers' responses to salary incentives and school characteristics by qualifications

Beyond technology and finance: pay-as-you-go sustainable energy access and theories of social change

Two-thirds of people in sub-Saharan Africa lack access to electricity, a precursor of poverty reduction and development. The international community has ambitious commitments in this regard, e.g. the UN's Sustainable Energy for All by 2030. But scholarship has not kept up with policy ambitions. This paper operationalises a sociotechnical transitions perspective to analyse for the first time the potential of new, mobileenabled, pay-as-you-go approaches to financing sustainable energy access, focussing on a case study of pay-as-you-go approaches to financing solar home systems in Kenya. The analysis calls into question the adequacy of the dominant, two-dimensional treatment of sustainable energy access in the literature as a purely financial/technology, economics/ engineering problem (which ignores sociocultural and political considerations) and demonstrates the value of a new research agenda that explicitly attends to theories of social change – even when, as in this paper, the focus is purely on finance. The paper demonstrates that sociocultural considerations cut across the literature's traditional two-dimensional analytic categories (technology and finance) and are material to the likely success of any technological or financial intervention. It also demonstrates that the alignment of new payas- you-go finance approaches with existing sociocultural practices of paying for energy can explain their early success and likely longevity relative to traditional finance approaches

Effects of fractional doses of total body irradiation on semen of boars

The effects of ionizing radiation on biological systems are being investigated more each day due to the increasing industrial uses of atomic energy. The potential hazards to both prenatal and postnatal animals have not been completely determined. These effects on man and farm animals are of prime importance, but intentional experimental exposures of humans are not possible except in special cases. Most of the present day knowledge about human reactions to radiation has come from extrapolation of data derived from irradiation of lower animals and accidental exposures of humans. Therefore, the more information that can be obtained from every available species, the more valid are the extrapolations to man likely to be. One of the most pressing questions has been the effect of radiation on reproduction in farm animals. Does radiation permanently impair the reproductive ability of the male? Will fractionated doses be more deleterious than acute exposures? These are but two of the many questions which must be answered. This study was initiated to determine the effects of fractionated doses of gamma radiation on sperm production and hematological elements in boars

The Extent of the White Chuck Tuff, a High Temperature Pyroclastic Flow Deposit, Glacier Peak, Washington

The White Chuck Tuff, a massive deposit approximately 15 m thick, caps two terraces in the White Chuck River valley covering an area of approximately 5 km2 at the base of Glacier Peak, Washington. Three major post-glacial eruption cycles from Glacier Peak reportedly occurred approximately from 12,000 to 11,250 years ago (White Chuck Assemblage), from 5,500 to 5,100 years ago (Kennedy Creek Assemblage), and from 1,800 to 250 years ago (recent eruptions). West of Glacier Peak, pyroclastic and lahar deposits from all three episodes are found in drainages out to Puget Sound 100 km away. The White Chuck Tuff has been assumed to be approximately 11, 500 years old (Beget, 1981) and not found west of Camp Creek in the White Chuck River Valley, approximately 17 km from Glacier Peak. Anisotropy of magnetic susceptibility, paleomagnetic, petrographic, and geochemical procedures were conducted to characterize the tuff deposit. Similar laboratory procedures were conducted on five distal pyroclastic deposits to determine if they were unconsolidated runout of the White Chuck Tuff. Flow direction, paleomagnetic directions and paleomagnetic poles, mineralogy, and chemical composition of the proximal indurated White Chuck Tuff indicate that it was emplaced as a single unit at temperatures exceeding 580° C. The overall flow direction during emplacement was northwesterly down the White Chuck River Valley. The paleomagnetic directions, mineral and chemical compositions are similar amongst the seven sampling sites. Five distal deposits WC-1, SR-1, SR-2, SR-3, and ST-1 were products of cold to warm (from 22°C to 375°C) debris flows that made their way down the White Chuck River Valley into the Sauk and North Fork Stillaguamish River Valleys. The paleomagnetic directions amongst the distal deposits were not well defined. The anisotropy of magnetic susceptibility of these deposits had no preferred orientation of the magnetic fabric indicating that the flow direction and individual clast anisotropy were independent of emplacement mechanisms. A viscous magnetization was measured in many of the pumiceous clasts sampled at all of the cooler distal sites and upward directions were measured in the low unblocking temperature range of 100 to 300° C in many of the samples from these sites. The clasts from these deposits had a previous magnetic history before they came to rest at their present location. The chemistry and mineralogy of all five distal sites is similar and indicate dacitic composition. The virtual geomagnetic pole of distal deposit WC-1 closely corresponds with the 9180 +290/-200 virtual geomagnetic pole of Hagstrum and Champion (2002), which post dates the White Chuck Assemblage. Virtual geomagnetic poles of other distal deposits are not well enough defined to be useful. From field relationships associated with the deposition and location of other deposits (Dravovieh et al, 2003), the Glacier Peak distal deposits were probably produced during the Kennedy Creek Assemblage eruption cycle. The virtual geomagnetic pole of the White Chuck Tuff deposit matches the 12,750 b.p. virtual geomagnetic pole of Hagstrum and Champion (2002). This virtual geomagnetic pole dates the tuff\u27s deposition before the White Chuck Assemblage eruptive cycle. Therefore the previously assumed age of 11,500 b.p. is probably incorrect

Are Teacher Absences Worth Worrying About in the U.S.?

Using detailed data from North Carolina, we examine the frequency, incidence, and consequences of teacher absences in public schools, as well as the impact of an absence disincentive policy. The incidence of teacher absences is regressive: schools in the poorest quartile averaged almost one extra sick day per teacher than schools in the highest income quartile, and schools with persistently high rates of teacher absence were much more likely to serve low-income than high-income students. In regression models incorporating teacher fixed effects, absences are associated with lower student achievement in elementary grades. Finally, we present evidence that the demand for discretionary absences is price-elastic. Our estimates suggest that a policy intervention that simultaneously raised teacher base salaries and broadened financial penalties for absences could both raise teachers' expected income and lower districts' expected costs.

Teacher Credentials and Student Achievement in High School: A Cross-Subject Analysis with Student Fixed Effects

We use data on statewide end-of-course tests in North Carolina to examine the relationship between teacher credentials and student achievement at the high school level. The availability of test scores in multiple subjects for each student permits us to estimate a model with student fixed effects, which helps minimize any bias associated with the non-random distribution of teachers and students among classrooms within schools. We find compelling evidence that teacher credentials affect student achievement in systematic ways and that the magnitudes are large enough to be policy relevant. As a result, the uneven distribution of teacher credentials by race and socio-economic status of high school students -- a pattern we also document -- contributes to achievement gaps in high school.

The Academic Achievement Gap in Grades 3 to 8

Using data for North Carolina public school students in grades 3 to 8, we examine achievement gaps between white students and students from other racial and ethnic groups. We focus on successive cohorts of students who stay in the state's public schools for all six years, and study both differences in means and in quantiles. Our results on achievement gaps between black and white students are consistent with those from other longitudinal studies: the gaps are sizable, are robust to controls for measures of socioeconomic status, and show no monotonic trend between 3rd and 8th grade. In contrast, both Hispanic and Asian students tend to gain on whites as they progress through these grades. Looking beyond simple mean differences, we find that the racial gaps in math between low-performing students have tended to shrink as students progress through school, while racial gaps between high-performing students have widened for black and American Indian students.

Teacher-Student Matching and the Assessment of Teacher Effectiveness

We use administrative data on North Carolina public schools to document the tendency for more highly qualified teachers to be matched with more advantaged students, and we measure the bias this pattern generates in estimates of the impacts of various teacher qualifications on student achievement. One of the strategies we use to minimize this bias is to restrict the analysis to schools that assign students to classrooms in a manner statistically indistinguishable from random assignment. Using data for 5th grade, we consistently find significant returns to teacher experience in both math and reading and to licensure test scores in math achievement. We also find that the returns in math are greater for socioeconomically advantaged students, a finding that may help explain why the observed form of teacher-student matching persists in equilibrium.