It's significantly harder to buy a home now than it was 1 year ago

The National Association of Realtors' monthly affordability index has plunged 17% since November 2017

A typical U.S. family in November had significantly more difficulty purchasing an existing family home at the national median price than one year ago, according to the National Association of Realtors latest monthly affordability index, released Friday.

The affordability index reached 144, meaning the typical family possessed 144 percent of the estimated income required to purchase a home. While that may sound promising, the affordability index is actually down 2.9 percent month-over-month and down 17 percent from November 2017.

Regionally, the West was the toughest region to buy a home, with the affordability index at just 105. In the midwest, the typical family possessed 181.9 of the estimated income to purchase a home, the easiest region to afford a home.

The typical median family homes in the United States reached $260,500 in November, up over the last two months but still down from the highs during the summer months. The effective loan rate on closed homes reached 4.99 percent however, the highest its been all year.

The index measures whether or not the typical family – defined as one earning the median family income as reported by the U.S. Bureau of the Census — could afford a typical home, which is defined as the national median-priced existing single-family home.

A value of 100 means that the typical family has enough income to qualify for a mortgage on a median-priced home, assuming a 20 percent downpayment and that the payment to income ration cannot exceed 25 percent of the median family income.