The rate of return represents a measure of the returns obtained, over time, relative to the costs of the initial investment in education. More specifically, the social internal rate of return is equal to the discount rate that equalises the social costs of education to the social benefits of education. The social costs of education include the opportunity cost of having people not participating in the production of output and the full cost of the provision of education, rather than just the cost borne by the individual. The social benefits include increased productivity associated with the investment in education and a host of possible non-economic benefits such as lower crime, better health, more social cohesion and more informed and effective citizens. See also Private internal rate of return and Fiscal internal rate of return.