The State Similarity Index attempts to quantify how similar states are to each other relative to other states. The index is a statistically-based way to measure this. 20% of the index is based on demographics. 10% of a state’s demographic score (2% of the overall State Similarity Index) is allocated for the age of its people. The following is an explanation on how the score was calculated.
Median Age
Maine, Vermont, New Hampshire, and West Virginia are states with the oldest median age in the country. The median age of their people is above 42 years old. All four states are very rural and located in the Appalachian Mountains. They are also among the states with the highest percentages of White people. Still, the state with the lowest median age, Utah, also has a high percentage of Whites. However, one big difference is that the majority of people in Utah are Mormon. Raising large families is one tradition they still practice. Utah’s median age is 32, over 3 years younger than the next youngest state, Texas.
Source: US Census Bureau
States were grouped into the following median age ranges:
31.25-32.5, 32.5-33.75, 33.75-35, 35-36.25, 36.25-37.5, 37.5-38.75, 38.75-40, 40-41.25, 41.25-42.5, 42.5-43.75, 43.75-45
Elderly Population
The percentage of elderly people (ages 65+) is highly correlated with the median age of the state. However, there are some subtle differences. Florida and Hawaii both make the top 5 list, since many people in the United States move to tropical locations with lots of coastline for their retirement.
Source: Kaiser Family Foundation
States were grouped into the following categories by percentage of senior citizens:
11-13, 13-15, 15-17, 17-19, 19-21, 21-23
Youth Population
The percentage of children (under the age of 18) is another statistic that is highly correlated with the median age of the state. The New England has an especially low percentage of children. Not only do the rural states in the region have few children, but also Massachusetts and Rhode Island. These states are among the least religious in the country.
Source: Kaiser Family Foundation
States were grouped into the following categories by percentage of children:
19-21, 21-23, 23-25, 25-27, 27-29, 29-31
