Whether rich or poor, residents of the United States or China, illiterate or college graduates, parents who have books in the home increase the level of education their children will attain, according to a 20-year study led by Mariah Evans, University of Nevada, Reno associate professor of sociology and resource economics.

For years, educators have thought the strongest predictor of attaining high levels of was having who were highly educated. But, strikingly, this massive study showed that the difference between being raised in a bookless home compared to being raised in a home with a 500-book library has as great an effect on the level of education a child will attain as having parents who are barely literate (3 years of education) compared to having parents who have a university education (15 or 16 years of education). Both factors, having a 500-book library or having university-educated parents, propel a child 3.2 years further in education, on average.

Being a , Evans was particularly interested to find that of lesser-educated parents benefit the most from having books in the home. She has been looking for ways to help Nevada's , in terms of economic development and education.

"What kinds of investments should we be making to help these kids get ahead?" she asked. "The results of this study indicate that getting some books into their homes is an inexpensive way that we can help these children succeed."

Evans said, "Even a little bit goes a long way," in terms of the number of books in a home. Having as few as 20 books in the home still has a significant impact on propelling a child to a higher level of education, and the more books you add, the greater the benefit.

"You get a lot of 'bang for your book'," she said. "It's quite a good return-on-investment in a time of scarce resources."

In some countries, such as China, having 500 or more books in the home propels children 6.6 years further in their education. In the United States, the effect is less, 2.4 years, than the 3.2-year average advantage experienced across all 27 countries in the study. But, Evans points out that 2.4 years is still a significant advantage in terms of educational attainment.

For example, according to the U.S. Census Bureau's American Community Survey, Americans who have some college or an associate's degree, but not a bachelor's degree, earn an average of $7,213 more annually than those with just a high school education. Those who attain a bachelor's degree earn $21,185 more each year, on average, than those with just high school diplomas.

The study by Evans and her colleagues at Nevada, UCLA and Australian National University is one of the largest and most comprehensive studies ever conducted on what influences the level of education a child will attain.

The researchers were struck by the strong effect having books in the home had on children's educational attainment even above and beyond such factors as of the parents, the country's GDP, the father's occupation or the political system of the country.

Having books in the home is twice as important as the father's education level, and more important than whether a child was reared in China or the United States. Surprisingly, the difference in educational attainment for children born in the and children born in China was just 2 years, less than two-thirds the effect that having 500 or more in the home had on children (3.2 years).

More information: The study, "Family scholarly culture and educational success: Books and schooling in 27 nations," was published in the journal, Research in Social Stratification and Mobility.

Provided by University of Nevada, Reno