ABSTRACT This paper examines the effects of knowledge about a wide variety of subjects on the wages and salaries of U.S. workers. Knowing a lot about topics such as medicine and dentistry, engineering and technology, and production and processing has a positive effect on individual earnings, whereas high knowledge in the areas of food production and personnel and human resources is not rewarded in the labor market. Spillover effects, where the share of metropolitan area employment in high-knowledge occupations enhances earnings, were uncovered primarily in subjects related to producer services and information technology.