The Effects of Class Size on the Long Run Growth in Reading Abilities and Early Adult Outcomes in the Christchurch Health and Development Study

This paper utilizes the feature of the CHDS data from New Zealand that children are sampled for extremely long individual histories of their class size experiences as well as their scholastic and early labor market outcomes. Our interest is to explore the full set of empirical implications of the recent experimental evidence on class size effects on student achievement from the United States in Project STAR for observational data. We argue that one implication of Project STAR is that only persistent class size reduction policies may have detectable effects, and so the longitudinal aspect of CHDS is necessary to detect class size effects. We account for the observational nature of the CHDS (in that children were not randomly assigned to different class sizes) by examining the long-run trends in test score growth, rather than levels. Consistent with the experimental evidence, we find statistically and economically significant effects of children being assigned to persistently smaller classes on both childhood test score growth as well as on early adult outcomes. Our analysis points the way towards the unification of experimental and observational evidence on class size effects, as well as highlighting several possible pitfalls in the analysis of observational data on this topic.School Quality; Value-Added Model; Experimental Evidence

The Relationship Between Subjectively Motivational Music and Various Exercise Variables While Running At Maximal Speed

Purpose: To determine whether there are differences in steps/min/m, highest achieved exercise heart rate, average exercise heart rate, average running speed, estimated relative VO2, and RPE, while listening to subjectively motivating music, as compared to non-motivating music, while running at max speed. Methods: Eleven students enrolled at the University of Massachusetts Boston, considered “non-runners” from 19 to 34 years of age, ran at max speeds for 12-15 minutes, once while listening to a play-list of songs they ranked most motivating, and a second time on a separate day, while listening to a play-list of songs they ranked least motivating. All participants were tested for steps/min/m, highest achieved exercise heart rate, average exercise heart rate, average running speed, estimated relative VO2, and RPE. Results: There were no statistically significant mean differences (p \u3e 0.05) between the “High” run (participant’s highest ranked motivational songs), and “Low” run (participant’s lowest ranked motivational songs), for steps/min/m, RPE, highest achieved exercise heart rate, average exercise heart rate, average running speed , and estimated relative VO2. There were statistically significant differences (p = 0.01) between participants’ “High” and “Low” runs for steps/min/m, after excluding outliers. Conclusion: There were no significant mean differences in steps/min/m, highest achieved exercise heart rate, average exercise heart rate, average running speed, estimated relative VO2, and RPE while listening to subjectively motivating music, as compared to non-motivating music, while running at max speed in “non-runners”

“One of the best advertising mediums the country can have:” Postage Stamps and National Identity in Canada, New Zealand and Australia

This article examines the transformation of postage stamp imagery in Canada, New Zealand and Australia from the late 19th century to the 1990s. It documents the manner in which this imagery evolved from a predominately ethnic representation during the first half of the 20th century to a preponderance of civic–nationalistic designs in the post-1960s period. By highlighting the largely similar ways in which the governments of these three nations used postage stamps to guide and reflect the revision of their respective national identities, the article seeks to encourage greater comparative work among scholars examining the political and cultural histories of these nations. It also emphasizes the utility of recognizing postage stamps as rich primary sources of material culture that can facilitate comparative research that focuses on broad temporal and geographic parameters.Cet article examine la transformation de l’imagerie des timbres-poste au Canada, en Nouvelle-Zélande et en Australie de la fin du XIXe siècle jusqu’aux années 1990. Il documente la façon dont cette imagerie a évolué, passant d’une représentation principalement ethnique au cours de la première moitié du XXe siècle à une prépondérance de dessins de style civique et nationaliste après les années 1960. En mettant en relief les façons semblables, mais parfois différentes, dont les gouvernements de ces trois nations ont utilisé les timbres-poste pour former et pour refléter la révision de leurs identités nationales respectives, l’article cherche à encourager un traitement comparatif de l’histoire politique et culturelle de ces nations chez les scientifiques examinant ces questions. Il souligne aussi l’utilité de reconnaître les timbres-poste comme de riches sources primaires de la culture matérielle susceptibles de faciliter la recherche comparative qui fait porter le regard sur de plus larges paramètres temporels et géographiques

Exit, Voice, and the Role of Corporate Directors: Evidence from Acquisition Performance

This study examines the characteristics of corporate boards for 82 companies that attempted 106 acquisitions during the 1980s. We find that poor performance is more likely to occur in firms that have recently experienced higher turnover of outside and lower turnover of inside directors. Companies with smaller boards, more reputable members, and larger equity holdings also outperform their counterparts. Our results do not suggest that more outside directors lead to improved performance but that outsiders often resign from the board instead of challenging managerial shirking. We conclude that choosing directors for whom board exit is costly will better reduce agency costs.

Retrofitting O'Raifeartaigh Models with Dynamical Scales

We provide a method for obtaining simple models of supersymmetry breaking, with all small mass scales generated dynamically, and illustrate it with explicit examples. We start from models of perturbative supersymmetry breaking, such as O'Raifeartaigh and Fayet models, that would respect an $R$ symmetry if their small input parameters transformed as the superpotential does. By coupling the system to a pure supersymmetric Yang-Mills theory (or a more general supersymmetric gauge theory with dynamically small vacuum expectation values), these parameters are replaced by powers of its dynamical scale in a way that is naturally enforced by the symmetry. We show that supersymmetry breaking in these models may be straightforwardly mediated to the supersymmetric Standard Model, obtain complete models of direct gauge mediation, and comment on related model building strategies that arise in this simple framework.Comment: 15 pages, harvmac bi

Launch Decisions of Pharmaceutical Companies

This paper models the launch decision of pharmaceutical companies in regard to new drugs and country markets. New drugs are launched with a delay or not launched at all in many countries. Considering that many of these new drugs would have created health benefits to the patients, there seems to be welfare loss. We use market characteristics to explain this phenomenon. We show that most of the estimated launch with a delay and no-launch decision is due to observable market characteristics. The model has an accuracy of 70 percent in explaining the no-launch decision. Intellectual property rights protection is especially important. The policy implication is that stronger property rights increase the likelihood and speed of new drug launch

A recent history of thermal barrier coatings for aero-propulsion applications

Thermal barrier coatings for aero-propulsion operation have been in use since the 1960s. These thermal barrier coatings are composed of an oxidation resistant metallic base layer and a thermally resistant ceramic top layer. The development and implementation of advances in both the metallic base and the ceramic top layer will be explored. The evolution has included performance and durability improvements, process advances, and understanding and evolution of failure modes. More recent efforts have focus on future challenges for thermal barrier coatings to meet ever increasing operating temperature demands of future applications