Walmart’s new parental leave policy is more generous than what’s on offer at most companies. That matters, because the United States is the only country in the world without paid maternity leave, and because Walmart is the largest employer in the U.S. While Walmart has stressed the smart business reasons for offering leave — greater productivity, engagement, and retention — it often still takes work on the part of employees to advocate for a benefit like this one. Advocacy groups say there are four ways employees can make a strong case. First, show broad employee support for changing the policy. Second, collect stories of real employees who’ll be affected; they’re often more persuasive than dry data. Third, put together a strong proposal for executives to react to. What do you think the policy should be, and what will it cost? And fourth, be persistent. This might take a while.