Double burden is a term used to describe the workload of people who work to earn money, but who are also responsible for significant amounts of unpaid domestic labor. This phenomenon is also known as the The Second Shift as in Arlie Hochschild's book of the same name. In heterosexual couples where both partners have paid jobs, women often spend significantly more time than men on household chores and caring work, such as childrearing or caring for sick family members. This outcome is determined in large part by traditional gender roles that have been accepted by society over time. Labor market constraints also play a role in determining who does the bulk of unpaid work.