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Presidential elections are often seen as referendums on the health of the economy; however, little evidence exists on the president's ability to influence gross domestic product (GDP). This study examines the effect of the incentive to be reelected and the resulting increase in presidential effort on GDP growth. Growth is found to rise in reelection years for first‐term presidents after 1932 and to fall in election years before 1932, when reelection was uncommon, and for second‐term presidents generally. This effect is largest for high‐quality presidents—who probably have the highest return to effort—and is spread across multiple sectors of the economy. (JEL D78, D72, E32, J24)  相似文献   
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A sample size justification should be given for all clinical investigations. However, sometimes the objective of a trial is to estimate an effect with a view to planning a later definitive study. This paper describes the calculations for designing studies where one wishes to adopt an estimation approach through using confidence intervals around the overall response. Calculations are given for data anticipated to take a Normal form. Copyright © 2004 John Wiley & Sons, Ltd.  相似文献   
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In non-experimental research, data on the same population process may be collected simultaneously by more than one instrument. For example, in the present application, two sample surveys and a population birth registration system all collect observations on first births by age and year, while the two surveys additionally collect information on women’s education. To make maximum use of the three data sources, the survey data are pooled and the population data introduced as constraints in a logistic regression equation. Reductions in standard errors about the age and birth-cohort parameters of the regression equation in the order of three-quarters are obtained by introducing the population data as constraints. A halving of the standard errors about the education parameters is achieved by pooling observations from the larger survey dataset with those from the smaller survey. The percentage reduction in the standard errors through imposing population constraints is independent of the total survey sample size.  相似文献   
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When the public relations firm D-A-Y was dissolved into Ogilvy & Mather Public Relations November 1, 1988, the longest lived public relations agency disappeared into the sands of time that enveloped the first four agencies started in the first decade of the waning century. The D in D-A-Y stood for Pendleton Dudley, a venerable pioneer in this vocation, who had opened his agency in Wall Street in 1909 at the urging of his good friend, Ivy Lee. Dudley, a rugged, independent product of frontier America, headed his firm for fifty-seven years—a longevity record surpassed only by that of Edward L. Bernays, who started his firm in 1919 in the Post World War I public relations boom.Pendleton Dudley—known to his close friends as Pen and to his associates in his firm as PD, was born September 8, 1876, in a small frontier town of Troy, Missouri, when America was an agricultural nation. He came to pioneer as a counselor to the corporate giants, AT&T among them, in a complex, interdependent corporate industrial America. Pen Dudley did much to infuse this field with respectability in a time when it was viewed with suspicion or disdain in its early years. He was a strong advocate of research as the only sound basis for planning and executing programs to influence public behavior. He was also active in the Public Relations Society of America after it was formed in 1948 and was in the forefront of those creating the now extinct Foundation for Public Relations Research and Education. In 1965, he received the Distinguished Service Award from the New York PRSA Chapter. He died at the age of 90 in 1966.The author is Dean Emeritus of Journalism at the University of Georgia, and co-author Effective Public Relations, 6th Ed.  相似文献   
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