On-the-Job Training surveys the recent literature from both a theoretical and empirical perspective. The analysis of how individuals obtain and are paid for their skills is fundamental to labour economics. The basic idea of human capital theory is that workers and firms invest in workers' skills in order to increase their productivity, much as persons invest in financial or physical assets to earn income. Workers develop many skills through formal education not tied to an employer, but an important part of their skills are learned on the job. The book focuses on recent literature including empirical research using direct measures of training and theoretical papers inspired by findings from this empirical work. The authors presents a theoretical model showing that costs and returns to general human capital may be shared if training increases mobility costs, if there are constraints on lowering wages, or if there is uncertainty about the value of training at competing employers. This model analyzes the choice of the amount of training, emphasizing the influence of whether the employer can commit to training prior to employment. In addition, the model implies that firms will attempt to match low-turnover workers with training opportunities, which is supported by the empirical literature.