Skill is a measure of the amount of worker's expertise, specialization, wages, and supervisory capacity. Skilled workers are generally more trained, higher paid, and have more responsibilities than unskilled workers. Skilled workers have long had historical import (see Division of labor) as masons, carpenters, blacksmiths, bakers, brewers, coopers, printers and other occupations that are economically productive. Skilled workers were often politically active through their craft guilds.