March is celebrated internationally as Women’s History Month, with the eighth day marked as International Women’s Day. Social media users have been known to post pictures of their heroes, ranging from Malala to Oprah to Marie Curie and draw attention to the long history of exclusion women endured. For much of American history, the only job women could legally have outside the home was school teaching, and they were paid pennies on the dollar for what male teachers made. Wartime necessities demanded that women enter the labor force in droves in the 1920s through the 1940s, but upon the return of the soldiers, women were once again pushed out of the working world.

Today, lots of legislation prevents the blatant gender discrimination that was once common practice, but there continue to be lots of loopholes. Many continue to claim that a “gender wage gap” inhibits women’s economic progress, especially for women of color or immigrant women. At the JP Morgan Healthcare Conference, men named Michael outnumbered women named anything. Clearly, there’s still work to be done.

As it turns out, there are strong economic and business reasons why companies should hire and invest in women beyond just being able to tout diversity and inclusion. They bring valuable assets to the company culture and can prove irreplaceable as members of your team. Data analyzers such as Gallup, Pew, and 538 have investigated the necessity of women in business, and the results couldn’t be clearer: women make business better. Here’s how:

Diversity Increases Engagement | One of the most valuable measures by which a company is evaluated is the engagement level of its employees. For decades, studies have demonstrated that engaged employees are more productive, more loyal to the company, and improve the business standing of the organization. A 2017 Gallup poll indicated that, in companies where diversity and inclusion experienced double the employee engagement that their non-diversity-focused did.

Flexible Companies are Sustainable Companies | One of the side effects of ensuring that your office is accommodating to women is ensuring time flexibility. By and large, in the US, women are the ones tasked with staying home with a sick child, working around school delays, and generally handling family business, and as such, companies need to find ways to be flexible around those important family needs. This need for “time flexibility” has often born the blame for the “gender wage gap,” but companies that have adapted have experienced less turnover and happier employees, as men and women alike can make more time for their families. They are also more attractive to other women and young people with lives to balance.

Innovation | The number one reason people cite for the importance of diversity is the “new perspectives” that women and non-White employees bring to the table. From their socioeconomic status to their educational experiences and beyond, people from diverse backgrounds are able to bring concerns that others may not have thought of. Mellody Hobson encouraged businesses to look for whose voice is not in the room and ensure that there is representation for them, too. Especially since women make most of the spending decisions in a household and combined control trillions of dollars of the economy, it’s imperative that businesses ensure that their decision and business plans account for the decision-making strategies of a crucial market segment.