"in 1999 to promote democratic debate on the most important economic and social issues that affect people's lives. In order for citizens to effectively exercise their voices in a democracy, they should be informed about the problems and choices that they face. CEPR is committed to presenting issues in an accurate and understandable manner, so that the public is better prepared to choose among the various policy options." If this report is an example of accuracy, then they are still learning their job. The graph is pretty unfortunately it is wrong.
If you read the entire report you find that the report misses the substance of both state and federal law. For example, the Fair Labor Standards Act requires overtime pay for labor in excess of 40 hours per week. Many states modify the FSLA provision so that the bonus rate applies after 8 hours in a day (see for example the provisions of California's AB 60). There are also a whole series of provisions in federal and state law which offer leave, paid and unpaid (again varying by state law) for things like family and bereavement. Obviously, none of that is vacation time.
The report also argues that there is discrimination based on income. Higher paid employees get more vacation. It claims that only 49% of low wage workers get paid vacation. They laud the EUs "working time directive" which establishes minimum requirements in law that EU members must follow. Many of those provisions are covered in labor contracts in the US.
The most important tradeoff here is whether having a federal standard would actually improve the lives of lower paid workers. Most large employers in the US (certainly many national companies that hire lots of hourly workers) offer some kind of vacation accrual and holiday pay as a way to stay competitive. For example, McDonalds offers 10 days a year for all but the most marginal employees. They also offer sabbaticals and bonus paid weeks off for every five years of service. Walmart which is often a target of the left, on a page called For Respect, offers vacation accruals for all employees. Vacation accruals increase as a person works more and as their time with the company increases.
Perhaps the way that the 49% was calculated was on number of employees not on hours worked. Even then the statistic lack validity. The tradeoff here is that lack of a federal standard most likely assures more opportunities for people entering the workforce and for the most casual seasonal workers. Does the CEPR actually think that is a bad thing?