Blume-Kohout Margaret E, Clack John W
Robert Wood Johnson Foundation Center for Health Policy and Department of Economics, University of New Mexico, Albuquerque, New Mexico, United States of America.
PLoS One. 2013 Dec 23;8(12):e82759. doi: 10.1371/journal.pone.0082759. eCollection 2013.
The U.S. National Institutes of Health (NIH) budget expansion from 1998 through 2003 increased demand for biomedical research, raising relative wages and total employment in the market for biomedical scientists. However, because research doctorates in biomedical sciences can often take six years or more to complete, the full labor supply response to such changes in market conditions is not immediate, but rather is observed over a period of several years. Economic rational expectations models assume that prospective students anticipate these future changes, and also that students take into account the opportunity costs of their pursuing graduate training. Prior empirical research on student enrollment and degree completions in science and engineering (S&E) fields indicates that "cobweb" expectations prevail: that is, at least in theory, prospective graduate students respond to contemporaneous changes in market wages and employment, but do not forecast further changes that will arise by the time they complete their degrees and enter the labor market. In this article, we analyze time-series data on wages and employment of biomedical scientists versus alternative careers, on completions of S&E bachelor's degrees and biomedical sciences PhDs, and on research expenditures funded both by NIH and by biopharmaceutical firms, to examine the responsiveness of the biomedical sciences labor supply to changes in market conditions. Consistent with previous studies, we find that enrollments and completions in biomedical sciences PhD programs are responsive to market conditions at the time of students' enrollment. More striking, however, is the close correspondence between graduate student enrollments and completions, and changes in availability of NIH-funded traineeships, fellowships, and research assistantships.
从1998年到2003年，美国国立卫生研究院（NIH）的预算扩张增加了对生物医学研究的需求，提高了生物医学科学家市场的相对工资和总就业人数。然而，由于生物医学科学领域的研究博士学位通常需要六年或更长时间才能完成，劳动力供应对市场条件变化的全面反应并非立竿见影，而是在几年的时间里才能观察到。经济理性预期模型假设未来的学生能够预见到这些未来的变化，并且学生们也会考虑到他们接受研究生培训的机会成本。先前关于科学与工程（S&E）领域学生入学率和学位完成情况的实证研究表明，“蛛网”预期占主导地位：也就是说，至少在理论上，未来的研究生会对市场工资和就业的同期变化做出反应，但不会预测到他们完成学位并进入劳动力市场时将会出现的进一步变化。在本文中，我们分析了生物医学科学家与其他职业的工资和就业的时间序列数据、科学与工程学士学位以及生物医学科学博士学位的完成情况，以及国立卫生研究院和生物制药公司资助的研究支出，以检验生物医学科学劳动力供应对市场条件变化的反应程度。与先前的研究一致，我们发现生物医学科学博士项目的入学率和完成率对学生入学时的市场条件有反应。然而，更引人注目的是研究生入学率和完成率与国立卫生研究院资助的培训、奖学金和研究助理职位的可获得性变化之间的密切对应关系。
