The question "Who will do science?" is one of growing urgency in the United States. Fewer U.S. college students are choosing to study math, science, and engineering - and half of those who do eventually switch to non-science majors. Moreover, U.S. students do not perform well on science and math achievement tests or in international competitions. If current trends continue, there will be a shortage of qualified candidates to fill the vacancies when scientists trained in the 1950s and 1960s retire. In Who Will Do Science? scholars and policy analysts from a variety of disciplines describe the present demographic situation, analyze the effectiveness of current programs for recruitment and retention, and examine policies that will improve the education of tomorrow's scientists and engineers. Topics discussed include the motives of students as they consider careers; the attitudes and influence of parents, teachers, and peers; the challenges faced by women and minorities; and the need for financial support during the lengthy training required to pursue careers in science.