The rate of existing home sales in the United States fell sharply in December, according to the National Association of Realtors. The drop came after two consecutive monthly increases in sales, but also marked the 10th month where sales were slower than the same time in the previous year.

The seasonally adjusted rate for existing home sales—including single-family homes, condominiums, townhomes, and co-ops—fell to 4.99 million. This was down 6.4 percent from November and 10.3 percent from December 2017.

Lawrence Yun, chief economist at the National Association of Realtors, said the slower pace of home sales was due in part to higher mortgage interest rates. According to Fannie Mae, the average commitment rate for a 30-year fixed rate mortgage in December was 4.64 percent, down from 4.87 percent in November but up from 3.99 percent for 2017 as a whole.

"The housing market is obviously very sensitive to mortgage rates. Softer sales in December reflected consumer search processes and contract signing activity in previous months when mortgage rates were higher than today," said Yun. "Now, with mortgage rates lower, some revival in home sales is expected going into spring."

The weekly average mortgage rate for a 30-year fixed rate mortgage fell to 4.45 percent on Jan. 24, according to Freddie Mac.

Home prices continued to increase, with the median price for existing home sales in December standing at $253,600. This was up 2.9 percent from December 2017, marking the 82nd straight month of year-over-year price gains.

The annual rate of single-family home sales slowed 5.5 percent from the previous month and 10.1 percent from the previous year to 4.45 million. The median price for this type of property was up 2.9 percent from December 2017 to $255,200.

The annual sales rate for condominiums and co-ops dropped 12.9 percent from November and 11.5 percent from December 2017 to 540,000 units. The median price for an existing condominium or co-op rose 2.3 percent from the previous year to $240,600.

Housing inventory continued to improve, with a total of 1.55 million existing properties for sale in December. While this was down from 1.74 million in November, it was up by 900,000 listings compared to the same time in the previous year.

"Several consecutive months of rising inventory is a positive development for consumers and could lead to a slower home price appreciation," said Yun. "But there is still a lack of adequate inventory on the lower-priced points and too many in upper-priced points."

Homes were also lingering on the market for longer periods of time. The typical property sold in December had spent 46 days on the market, four days slower than in the previous month and six days slower than in the previous year. Thirty-nine percent of existing homes sold in December had been listed for less than a month before finding a buyer.

The National Association of Realtors offered mixed reactions to the effect of the partial government shutdown, which began on Dec. 21 and ended on Jan. 25. In a survey of 2,211 of the organization's members, completed on Jan. 7, three-quarters of respondents said the shutdown was having no impact on their contract signings or closings. Twenty-two percent said the shutdown had an impact on current or potential clients, with these respondents most likely to say cite buyers' worrying about general economic uncertainty or closing delays associated with the shutdown.

"The partial shutdown of the federal government has not had a significant effect on December closings, but the uncertainty of a shutdown has the potential to harm the government," said John Smaby, president of the National Association of Realtors. "Once the government is fully reopened, I am hopeful that housing transactions will increase."

First-time buyers accounted for 32 percent of December's sales, unchanged from the previous year. This was down slightly from the 33 percent share recorded in both November and in the National Association of Realtors' 2018 Profile of Home Buyers and Sellers, an annual report released in late 2018.

Twenty-two percent of December's transactions were made without financing, up from 21 percent in November and 20 percent in December 2017. Individual investors, who account for many of these all-cash sales, made up 13 percent of December's sales – unchanged from the previous month and down from 16 percent in the previous year.

Distressed sales remained at record lows, making up just 2 percent of December's sales. This share of foreclosures and short sales was the same as in November and down from 5 percent in December 2017.

Existing sales were down in each of four geographic regions identified by the National Association of Realtors. In the Northeast, the rate of existing home sales fell 6.8 percent from both the previous month and previous year to 690,000. The median price for an existing home in the region increased 8.2 percent to $283,400.

The sharpest monthly decrease occurred in the Midwest, where the annual rate of 1.19 million sales was down 11.2 percent from November. This also marked a 10.5 percent decrease from the previous year. The median price in the region was unchanged from the previous year, remaining at $191,300.

The West had the largest year-over-year decrease, with the region's sales rate falling 15 percent from December 2017 to 1.02 million. The region had a more modest drop of 1.2 percent from November. The median home price in the region crept up 0.2 percent to $374,400.

In the South, the annual sales rate of 2.09 million was down 5.4 percent from the previous month and 8.7 percent from the previous year. The median price in the region increased 2.5 percent from December 2017 to $224,300.