Gender inequality is a lot like pollution. It’s human-made, harmful for everyone, and ubiquitous—although some places are worse off than others. A new study released today by the McKinsey Global Institute (MGI) identifies the best and worst states for gender equality in the workplace, and explains how leveling the playing field will improve not only our culture but also our economy. 

MGI is not a social justice organization; rather, it’s a think tank with a mission to educate world leaders about the factors that influence economics. Last year, the Institute published a report on the effects of gender disparities on the global economy [PDF]. They followed that up with another report focused solely on the gender-economy connection in India; and now they’ve turned their attention to the United States. “We chose to focus on the United States,” the authors wrote, “because, among developed economies, it can secure the largest economic advantage from addressing gender inequality.” In other words, we’ve got an awful lot to gain if we can just get our act together.

How much can we gain? About $4.3 trillion per year. That’s the amount America could add to our gross domestic product (GDP) by correcting gender disparities in our nation’s workforce by 2025, and it represents a 19 percent increase over what the GDP will be if we just keep on doing what we’re doing. And even if we can’t manage total equality, we could still add $2.1 trillion a year by bringing all states up to the level of gender equality seen in the most-equal state.

To calculate the level of equality (or lack thereof) in each state, MGI analysts considered ten factors: women's participation in the workforce, the types of jobs held by women, the number of women in leadership positions, unpaid work done by women, the number of single mothers, maternal mortality, higher education for women, teen pregnancy rates, women's political representation, and violence against women. 

As a whole, the U.S. scored poorly or extremely poorly on six out of ten items: leadership and managerial positions, unpaid care work, single mothers, teenage pregnancy, political representation, and violence against women.    

“To give an idea of the considerable challenges that the United States faces,” the authors wrote, “there are just 66 women for every 100 men in business leadership and managerial positions, women do almost double the unpaid care work that men do, and there is one incident of sexual violence for every two women in the United States.” 

All ten factors were considered at the state level and compiled into what MGI calls a state parity score between 0 and 1. Higher scores indicated more equal conditions, although “high” is relative, since all 50 states did pretty badly.

The 12 worst states, from worst to not-as-bad (remember, a high score is better):

Alaska (0.58)
Arkansas and Louisiana (0.59) 
Nevada, Oklahoma, Texas, South Carolina, Georgia, and Missouri (0.60) 
Utah and Nebraska (0.61) 
Kentucky (0.62) 

And the 12 best:

Maine (0.74)
New Hampshire, Connecticut, and Minnesota (0.70)
Hawaii, Arizona, and Massachusetts (0.69)
Montana (0.68)
Illinois, Indiana, North Carolina, and New York (0.67)

There are several points worth calling out here. First, there’s a fairly slim margin between the highest-ranked state (Maine, 0.74) and the lowest (Alaska, 0.58). Second, several of the highest-scoring states are in the Northeast, which is one of the most affluent parts of the country, while many of the low-scoring states are in the poorer Southeast—places that could benefit the most from the economic boost gender equality would bring.

The report noted that making these changes won’t be quick, and it won’t be cheap, but the long-term effects will be well worth the effort.