Pending sales in the United States dropped for the eighth consecutive month in August, according to the National Association of Realtors. However, the organization said there are also indications that more homeowners may be considering putting their home on the market, helping to alleviate persistent shortages in available homes for sale.

The Pending Home Sales Index for the month stood at 104.2. This was down 1.8 percent from July, marking the fourth month-over-month decrease in the past five months, while the figure also dropped 2.3 percent on an annual basis.

The index is a measure of transactions where a contract has been signed but the home sale has not yet closed. Since the sale is usually finalized within a couple of months, this measure is a good forward-looking measure of upcoming sales. A figure of 100 is equal to sales activity in 2001, which fell between 5 million and 5.5 million – a range considered normal for the current population of the United States.

Existing home sales have seen year-over-year decreases for six months in a row. In August, the seasonally adjusted annual sales rate for existing single-family homes, condominiums, co-ops, and townhomes was down 1.5 percent from the previous year to 5.34 million.

Lawrence Yun, chief economist at the National Association of Realtors, said the decline in sales is largely due to the low inventory of homes for sale. This has helped fuel higher home prices and stronger competition which, combined with a gradual increase in mortgage rates, has made affordability more of a challenge for buyers.

The National Association of Realtors' Housing Opportunities and Market Experience survey for the third quarter of 2018 indicated that 77 percent of respondents considered it a good time to sell a home – up from 63 percent in the previous year. At the same time, a dwindling number of respondents sees the market as favorable to buyers, with just 63 percent considering it a good time to buy – down 9 percentage points from the previous year.

"With prices having risen so quickly, many consumers were deciding to wait to list their homes hoping to see additional price and equity gains," said Yun. "However, with indications that buyers are beginning to pull out, price gains are going to decelerate and potential sellers are considering that now is a good time to list and bring more properties to the market."

August saw a modest increase in available homes for sale, after about three straight years of year-over-year decreases in inventory. There were 1.92 million homes for sale during the month – an increase in 50,000 properties from August 2017.

Yun said that while higher mortgage rates might prove a deterrent to buyers, he does not think they will result in a significant number of people backing out of the market.

"We have two opposing factors affecting the market: the negative impact of rising mortgage rates and the positive impact of continued job creation," said Yun. "This should lead to future home sales staying fairly neutral. As long as there is job growth, rising mortgage rates will hinder some buyers; but job creation means second or third incomes being added to households which gives consumers the financial confidence to go out and make a home purchase."

Yun's upgraded forecast expects that existing home sales will drop by 1.6 percent to 5.46 million in 2018, while the national median price for a home will grow 4.8 percent. In 2019, he predicts that existing home sales will increase by 2 percent while annual price growth will slow to 3.5 percent.

Pending sales were down in all but one of the four geographic regions outlined by the National Association of Realtors. The West had the most precipitous decline, as major price increases and a lack of inventory had the greatest deterrent effect on buyers. The region's Pending Sales Index fell 5.9 percent from the previous month and 11.3 percent from the previous year to 89.1.

The South was the only region with some increase in pending sales, with its index climbing 1.3 percent from August 2017 to 121.3. However, this was down 0.7 percent from July.

In the Northeast, the Pending Home Sales Index fell 1.3 percent from the previous month and 1.6 percent from the previous year to 92.7. The figure was down 0.5 percent from July and 1.1 percent from August 2017 in the Midwest, standing at 101.6.