The wealth gap between older and younger Americans has doubled in a 33-year period (from the early 1980s to 2013). The reason, reports Lawrence Yun, National Association of Realtors chief economist, is partly due to decreasing homeownership among young people.

Writing in Realtor magazine, Yun notes that in the early ‘80s, the median net worth of a household headed by someone under 35 was $15,260, compared to $120,500 when headed by someone over 65. “You would expect this roughly 10-to-1 wealth difference because people’s earning power and savings grow over time.” Homeownership contributes to this accumulation of wealth.

But as of 2013, the wealth gap between these generations doubled, to 20 to 1. The median net worth of a household headed by someone under 35 is now $10,500, compared to $210,500 for older households.

One cause, notes Yun, is that younger people have been putting off buying homes in recent years. The rate of homeownership in younger households has fallen to 34% from a recent peak of 43%. The percentage of first-time homebuyers has dropped to its lowest point in 30 years.

“Young people have it bad,” notes Yun. “Student loan debt is one reason. The burden has tripled over the past decade with recent graduates carrying an average of $29,000.” A recent survey, he writes, found that 71% of the graduates who are responsibly paying back their loans are delaying buying a home by 5 years, due to their debt.

To help solve the problem, NAR is backing a plan in Congress to refinance student loans into lower interest rates.