Does Head Start Improve Children’s Life Chances? Evidence from a Regression Discontinuity Design

This paper exploits a new source of variation in Head Start funding to identify the programs effects on health and schooling. In 1965 the Office of Economic Opportunity (OEO) provided technical assistance to the 300 poorest counties in the U.S. to develop Head Start funding proposals. The result was a large and lasting discontinuity in Head Start funding rates at the OEO cutoff for grant-writing assistance, but no discontinuity in other forms of federal social spending. We find evidence of a large negative discontinuity at the OEO cutoff in mortality rates for children ages 5-9 from causes that could be affected by Head Start, but not for other mortality causes or birth cohorts that should not be affected by the program. We also find suggestive evidence for a positive effect of Head Start on educational attainment in both the 1990 Census, concentrated among those cohorts born late enough to have been exposed to the program, and among respondents in the National Education Longitudinal Study of 1988.heat start, reform, labor

The effect of ionization on the infrared absorption spectra of PAHs: A preliminary report

The emission lines observed in many interstellar IR sources at 3.28, 6.2, 7.7, 8.7, and 11.3 microns are theorized to originate from polycyclic aromatic hydrocarbons (PAHs). These assignments are based on analyses of lab IR spectra of neutral PAHs. However, it is likely that in the interstellar medium that PAHs are ionized, i.e., are positively charged. Besides, as pointed out by Allamandola et al., although the IR emission band spectrum resembles what one might expect from a mixture of PAHs, it does not match in details such as frequency, band profile, or relative intensities predicted from the absorption spectra of any known PAH molecule. One source of more information to test the PAH theory is ab initio molecular orbital theory. It can be used to compute, from first principles, the geometries, vibrational frequencies, and vibrational intensities for model PAH compounds which are difficult to study in the lab. The Gaussian 86 computer program was used to determine the effect of ionization on the infrared absorption spectra of several small PAHs: naphthalene and anthracene. A preliminary report is presented of the results of these calculations

Bootstrap-Based Improvements for Inference with Clustered Errors

Microeconometrics researchers have increasingly realized the essential need to account for any within-group dependence in estimating standard errors of regression parameter estimates. The typical preferred solution is to calculate cluster-robust or sandwich standard errors that permit quite general heteroskedasticity and within-cluster error correlation, but presume that the number of clusters is large. In applications with few (5-30) clusters, standard asymptotic tests can over-reject considerably. We investigate more accurate inference using cluster bootstrap-t procedures that provide asymptotic refinement. These procedures are evaluated using Monte Carlos, including the much-cited differences-in-differences example of Bertrand, Mullainathan and Duflo (2004). In situations where standard methods lead to rejection rates in excess of ten percent (or more) for tests of nominal size 0.05, our methods can reduce this to five percent. In principle a pairs cluster bootstrap should work well, but in practice a Wild cluster bootstrap performs better.clustered errors; random effects; cluster robust; sandwich; bootstrap; bootstrap-t; clustered bootstrap; pairs bootstrap; wild bootstrap.

Continued fraction digit averages an Maclaurin's inequalities

A classical result of Khinchin says that for almost all real numbers $\alpha$, the geometric mean of the first $n$ digits $a_i(\alpha)$ in the continued fraction expansion of $\alpha$ converges to a number $K = 2.6854520\ldots$ (Khinchin's constant) as $n \to \infty$. On the other hand, for almost all $\alpha$, the arithmetic mean of the first $n$ continued fraction digits $a_i(\alpha)$ approaches infinity as $n \to \infty$. There is a sequence of refinements of the AM-GM inequality, Maclaurin's inequalities, relating the $1/k$-th powers of the $k$-th elementary symmetric means of $n$ numbers for $1 \leq k \leq n$. On the left end (when $k=n$) we have the geometric mean, and on the right end ($k=1$) we have the arithmetic mean. We analyze what happens to the means of continued fraction digits of a typical real number in the limit as one moves $f(n)$ steps away from either extreme. We prove sufficient conditions on $f(n)$ to ensure to ensure divergence when one moves $f(n)$ steps away from the arithmetic mean and convergence when one moves $f(n)$ steps away from the geometric mean. For typical $\alpha$ we conjecture the behavior for $f(n)=cn$, $0<c<1$. We also study the limiting behavior of such means for quadratic irrational $\alpha$, providing rigorous results, as well as numerically supported conjectures.Comment: 32 pages, 7 figures. Substantial additions were made to previous version, including Theorem 1.3, Section 6, and Appendix

Complicated lives of college students the educational culture of under-achievers

Titre de l'écran-titre (visionné le 4 oct. 2013)Bibliogr

Women, development and social change : the women of rural Malawi : a case study

This study explores the contradictions which arise between global market driven development and the lived reality of Malawi's rural women with respect to the critical elements of peasant life which are usually defined as land, labour and social regime. Policy makers and planners design programmes and projects to integrate the peasantry into the free market economy which emphasizes productivity, technology and cash returns. On the other hand, peasant farmers, particularly women, with their primordial responsibility for domestic reproduction, are faced with the need to feed their families and provide social supports not available through the market system. Poor women have little or no influence over the impact of the application of administrative policies which produce strain on the subsistence system, with which the population must cope by calling on the social regime which sustains them, albeit inadequately in the face of a restructured economy

The ITGLWF’s policy on cross-border dialogue in the textiles, clothing and footwear sector: Emerging strategies in a sector ruled by codes of conduct and resistant companies

The central problem for trade unions in the global textiles, clothing and footwear (TCF) sector is the absence of a mature system of industrial relations in most of the countries where production is located. From the perspective of the International Textile, Garment and Leather Workers’ Federation (ITGLWF) — the global union federation representing some 240 affiliated TCF unions in 110 countries — such a system is defined as the presence of well-organized workforces in supplier factories, organized by recognized, trained and independent trade union representatives able to engage in grievance and dispute resolution, as well as in periodic but regular collective bargaining with the management of production sites. In an industry with approximately 26 million workers in its formal sector (ILO, 2000), the extent to which industrial relations can be defined as “mature” is indeed very limited. Furthermore, official figures for union density in the sector are not available. 3 Thus, while the affiliated membership data for the ITGLWF in 2006 give a figure of 1.7 million, there is still an unspecified number of unions that have chosen not to affiliate to the global union federation for ideological or other reasons. Based on available data, a density figure of 12 per cent is probably exaggerated, when one takes into account the (very conservative) International Labour Organization (ILO) estimate of workers in the sector (which does not cover those informal parts of the industry) and other inaccuracies in the recording of membership. 4 Moreover, this figure masks major differences among unions in the various subsectors of the TCF sector. This chapter elaborates several major features of the TCF sector that present significant obstacles in the way of ITGLWF action aimed at organizing workers across borders. The first part provides data and examples that demonstrate, among other things, that the notion of “crossborder organizing” (euphemistically called “organizing along supply chains”— see below) appears to be over-optimistic and premature, to the extent that buyer-driven production chains are based on a very complex and opaque web of relations among the various tiers of outsourced production. The second part focuses on the strategy of the ITGLWF in the areas of multinational research and networking, which are viewed as a necessary step in any efforts to organize workers and pave the way towards a form of social dialogue across borders. The third section of the chapter outlines some reasons that explain the particular approach taken by the ITGLWF towards cross-border dialogue with multinational companies (MNCs) in the industry, including the absence of transparency of supply chains, the (mis)perception of codes of conduct as satisfactory forms of global social compliance, the rise of multi-stakeholder initiatives and the embedded culture of “union avoidance” in the industry. The final section outlines the background to the conclusion of the first international framework agreement (IFA) in the TCF sector with an MNC

ANALYSIS OF STAKEHOLDER EXPECTATIONS OF EFFECTIVE INDIANA HIGH SCHOOLS

The primary purpose of this study was to analyze expectations and perceptions from various groups concerning qualities of effective high schools. This study examined commonalities among groups of people in terms of their relationship to high schools. Stakeholders from Indiana surveyed during this study included: high school parents, high school educators, and state-level lawmakers, both senators and representatives. A total of 329 respondents participated in the study. After an extensive literature review of high school outcomes, characteristics, and purposes, I developed the Quality School Survey to collect the needed data. The instrument gathered data by asking respondents to indicate the level of importance on a four-point scale regarding multiple statements about high schools. The survey also presented the respondents with a list of 12 aspects of high schools and asked them to identify the top three priorities within that list. The data were collected and descriptive statistics were run to describe the level of importance placed on certain items by the overall sample and also the individual stakeholder groups. Frequency of selection within the prioritizing section was also described for the individual groups as well. Finally the data were put through an analysis of variance (ANOVA) to determine significant difference between the groups. The variation among the expectations of the different stakeholder groups was tested at the alpha level of .01. Based on the results and significant findings of the data analysis of the research, the following conclusions were drawn. There was an alignment between groups and a high level of expectation with regards to the teaching of basic skills, the teaching of problem-solving skills, the development of a safeenvironment, the promotion of work ethic, the development of citizenship, and community responsibility. Also, there was significant difference among groups and a high level of expectation with regards to preparing students for skilled employment upon graduation, using a variety of instructional strategies to accommodate individual learning styles, and developing social skills within students. An alignment and a low level of importance was placed on high schools being small in size to ensure a sense of belonging. Lawmakers had a significantly lower expectation level than parents with regards to developing social skills within students and ensuring emotional health of students. Lawmakers had a significantly lower expectation level than educators when it came to positive home–school relationships, having a vision and mission statement to guide decision-making, and teaching an appreciation of the arts within high schools. The highest priority among all groups when asked to select three from the list was promotion of work ethic within high school students. Finally, the lowest priority among all groups when asked to select three from the list was that the high school should have high standardized test scores