Oil Boom Brings Men to North Dakota
The U.S. State with the most lopsided gender ratio is North Dakota. This largely unknown state has gender ratio of 1.05, the second highest in the nation. This means that there are 105 men for every 100 women in the state. But for certain demographics, the ratio reaches as high as 1.23. The highest gender ratio is Alaska with a sex ratio of 1.11 (111 men to 100 women).
So what is causing the disproportionate amount of men to live in North Dakota? First, let us look at gender ratios at birth in North Dakota. For the age group of 0 to 4 years old, the North Dakota gender ratio is 1.05, only slightly above the nationwide average of 1.04. So an unusual gender ratios at birth is not the cause.
In most other states, we seen the gender ratios fall from an average of 1.04 in the 0-4 year old down to 1.00, meaning there are an equal number of men and women, by the 25 to 29 year old age group. In North Dakota, the story is much different. The gender ratio holds stead at 1.05 to 1.06 through the 10-14 year old age group. In the 20-24 year old age group the gender ratio climbs to 1.18 and then to 1.23 by the 25-29 year old age group. The gender ratio in North Dakota then remains higher than average until we reach the 80-84 year old group.
This unusual gender ratio pattern is likely do to the large number of shale oil drilling sites in North Dakota. Oil drilling a demanding job that attracts men in greater numbers than women. Jobs working in the oil fields are in high demand and pay quite well. As a result, men from other states and across the country are moving to North Dakota. This is why we see such an increase in men in North Dakota in the 20-29 year old age group. This is the age when most people start looking for careers like the ones available in the oil industry.
In addition to the gender ratios by age analysis, we can visual gender ratios on a map of North Dakota to get a better sense of the cause of this gender ratio disparity. By looking at the gender ratio visualization map of North Dakota we can see there are higher than average gender ratios in the Northwestern counties. Counties in the rest of the state seem to align with the national averages. By cross referencing our gender ratio map with a map of oil well locations in North Dakota, we see an identical pattern.
Reference: North Dakota Oil Well Map
The majority of oil wells in North Dakota are found in the Northwest part of the state. This further confirms our hypothesis that an abundance of jobs in the North Dakota oil fields is driving the high gender ratios in the state.
The gender ratio remains in favor of women (i.e. there are more men) until the age of 65-69. Not so coincidentally, this is the age when most people retire. After retiring, many men who had been working in the oil fields either move away or die.
Another interesting trend in the North Dakota Gender Ratios data is found in the 80-84 and 85+ age groups. In every other age group in North Dakota, the gender ratio is higher than the national average. For the 80-84 and 85+ age group, the ratio is lower than the national average. For the 85+ age group, the gender ratio dips as low as 0.51 — 51 men for every 100 women. This is a staggering shift in the gender ratios for people just 10 to 15 years younger.
What is causing this huge shift in the gender ratio? It is hard to say. Our research suggests that men in this region have largely worked difficult and physically demanding jobs in the oil drilling industry for many years. It is logical that these men would, on average, have a short life expectancy. Men already have a shorter life expectancy than women. The hard labor jobs that are abundant in North Dakota may exacerbate this gender disparity. This conclusion is consistent with our observations of the gender ratios for older North Dakotans.
Note: All numbers are based on the most recent data available at the time of writing (November 2015).
- Gender Ratios