Individual variation in labor supply can arise from more than just a choice among discrete occupation groups, especially given the joint process of wage determination and time allocation. Other factors can include differential preferences for earnings, the time length of work and other related occupational attributes. Using data from the Wisconsin Longitudinal Study (WLS), this study analyzes individual variation in labor supply for workers in their prime as a joint choice of weekly work hours, annual work weeks, and hourly earnings. The results present an alternative explanation for occupational choices and provide insights into potential policies for reducing wage differentials and adjusting labor supply. This paper then examines the linkages between education and occupation choice by looking at the dependence of people's occupational choice set on their major field of study and the association between the level of education and occupational activities. The existing literature on the linkage between human capital and occupational choice mostly tries to match workers' years of schooling with required years of schooling within an occupation. This study contributes to the current literature by constructing an index that indicates the transferability of skills acquired by different majors across occupations. This study then investigates how this index affects occupational change at mid-life. I find that specific skills decrease the probability of occupational change for women, however, the reverse was found for men. I also study the association between level of education and numerical occupational classifications as defined by Dictionary of Occupational Titles (DOT), and find that people with higher levels of education are likely to deal with greater complexity in data and people, and apply a higher level of reasoning, mathematics, and language. This study contributes to the synchronization of the education system and the labor market. The results encourage individuals to seek out the types of human-capital accumulation that promote their career aspirations and motivate policy-makers to efficiently evaluate spending on education and job-training programs. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]