Productivity describes the relationship between real output and the labor time involved in its production. Productivity shows the changes from period to period in the amount of goods and services produced per hour. Although productivity measures relate output to hours at work of all persons engaged in a sector, it do not measure the specific contribution of labor, capital, or any other factor of production. Rather, it reflects the joint effects of many influences, including changes in technology; capital investment; level of output; utilization of capacity, energy, and materials; the organization of production; managerial skill; and the characteristics and effort of the work force.