We invest our money downstream instead of upstream. We pour money into health care to try to treat poor health instead of upstream, which would invest money in health determinants, such as social or environmental factors, that would improve population health and prevent poor health. Health differences are used to describe objective, descriptive differences in health. Health disparities are avoidable differences in population health due to systematically entrenched factors, such as racism. The overall health pattern of an entire group or population as opposed to the health of individuals: the current average life expectancy in the state of michigan is 77. 9 years. The average life expectancy in ann arbor, mi is the highest in the state: 80. 5 years. It is the lowest in the state in battle creek, at 75. 8 years. The life expectancy for poor males in detroit is 74. 7 years.