Final answer:
In the labor market, signals are personal characteristics viewed as indicators of productivity. Employers use signals to make hiring decisions when they have imperfect information about a worker's productivity.
Step-by-step explanation:
In the labor market, signals are personal characteristics viewed as indicators of productivity. These characteristics can be acquired or innate. Employers often use signals to make hiring decisions when they have imperfect information about a worker's productivity. Examples of signals include education, training, work experience, references, awards, and a high grade point average.