Parents are eager to do everything they possibly can to help their children be successful. If you want your kids to earn big salaries as adults, what should you buy them now? Piano lessons? Coding camp? Mandarin class?

None of the above. A new study found the secret to your child’s future success could be far simpler–and more affordable–than any of those options. Instead, you should surround them with books. Real, physical, actual books. The kind with pages that turn and everything. It turns out that simply having access to plain old books at home has tremendous benefit for your kid’s future earning potential. Quartz reported on a new study, which found that boys who grow up around books earn significantly more as adults.

Economists from Italy’s University of Padova recently released the study, in which they compared data on 5,820 European men. The goal was to find out if an extra year of education contributed to their earning potential. It did, and those who as boys went to school for an additional year earned 9 percent more as adults.

But the researchers found something else surprising in the data. Those kids who had an extra year of school and had more than 10 nonschool books at home went on to double their lifetime earning advantage to upwards of 21 percent. It turns out that 10 was the magic number of books. Men who reported having had 50, 100, or 200 books at home weren’t any better off. “Factors like whether the boys’ fathers had white-collar jobs, and whether their homes had running water, did not seem to make a difference,” Quartz reported.

As with all studies, we need to be careful with extrapolating the data. Having an at-home library consisting of exactly 10 books as a child doesn’t guarantee you’ll earn a huge salary as an adult. There are likely several other factors at play that contributed to the success of the study participants.

It could be that those families with books were already more invested in their children’s education because they brought books into their home. Or, since parents had more books at the ready, perhaps their kids benefited from being read to more often. Or, these could have been wealthier families because they could afford to buy books in the first place.

Regardless of the correlation between the books and the results about earning a big salary, if this motivates you to bring more books home, your kids will certainly benefit in one way or another. Because you don’t need a study to prove the value of discovering the joy of getting lost in a good book.


This Article was Originally posted with INC. magazine. You can view this article HERE