It’s becoming harder and harder to rationalize buying a home instead of renting one, according to REALTOR.com’s Q4 2018 Rent vs. Buy Report. Affordability is tightening most everywhere and the number of markets where it’s cheaper to buy than rent is decreasing.

It is now more affordable to buy a home in only 17% of US counties, down from 25% in 2017. An average monthly mortgage payment is now $1,578, +13% higher than the same time last year when it was $1,398 and required 29% of the monthly national median income. The average monthly rental payment is now $1,267, an increase of +4% from last year’s rental payment.

REALTOR.com writes in its Q4 2018 Rent vs. Buy Report, “Pockets of affordability persist, but they’re getting harder to find. Many parts of the US have seen relative home-buying affordability erode away, thanks to rising home prices (up just under 6% in 2018 and forecast to rise by almost +5% y/y by September 2019, according to CoreLogic), rising interest rates (principal and interest mortgage payments on median priced homes rose by more than +16% in 2018 and are forecast to rise by more than +11% by September 2019, according to CoreLogic) and slower rising rents.”

“Still,” according to REALTOR.com, “while short-term math may be challenging, in the long term, rising rents tend to eventually outpace the cost of principal and interest on a fixed rate loan, which can make a home purchase the better long-term decision.”

The bottom line, according to REALTOR.com, is that inventory, especially in high-demand, short-supply lower tier housing, and affordability impact rent vs. buy decisions. Buying required 31% of average incomes in Q4 2018, 2% higher than the same period in 2017. What percentage of average incomes will be required for a median priced home in 2019?