The benefits of a signal of education on the job market are shown using the relative costs and benefits of a four-year degree to low-productivity and high-productivity workers. Low-productivity workers’ costs increase by $50,000 for every year of college, as shown by C_L. High-productivity workers’ costs, represented by C_H, are lower at $25,000 per year. At four years of college, the wage premium jumps from $0 to $125,000. In this market, high-productivity workers will attend exactly four years of college because the benefits of college outweigh the costs. Low-productivity workers will not attend college because the costs of education outweigh the benefits.