In Ukraine and other countries that ranked lower on the equality scale, men and women aren't getting as much sleep.
The findings suggest a country's efforts to empower women has positive effects on the individual level – for both men and women.
'Men experience countless benefits from gender equality, reporting better physical health, greater happiness, and – as our study shows – better sleep,' Ruppanner says.
'Women in more gender-equal countries also report better health as well as more equal divisions of child care and housework with their partners.
'Doing unpaid domestic work often comes at the expense of free time and self-care, so this more equitable division of labor is critical to women's sleep.'
In the study published to the Journal of Marriage and Family, the researchers say the findings highlight the importance of promoting gender equality on a national level – not just in the household.
The effects then trickle down into day-to-day life.
'Sleep, like housework and child care, is another way women's time is stretched, interrupted, and undervalued,' Ruppanner wrote.
'Women have to advocate for their own right to sleep and other forms of self-care. And second, we have to acknowledge gender inequality is bad for men too.
'Like child care, the financial pressures of work are detrimental to sleep. In countries with high gender equality, men aren't carrying the burden alone
'This means, when it comes to sleep, dismantling traditional gender norms is something men would benefit from nearly as much as women.'