Social factors play a significant role in developing health and illness. Studies of epidemiology show that autonomy and control in the workplace are vital factors in the etiology of heart disease. One cause is an effort-reward imbalance. Decreasing career advancement opportunities and major imbalances in control over work have been coupled with various negative health costs. Various studies have shown that pension rights may shed light on mortality differences between retired men and women of different socioeconomic statuses. These studies show that there are outside factors that influence health and illness.