Even though the time it takes to sell a luxury property has increased to as long as 260 days in Chicago, 287 in Miami and 197 nationally, fewer sellers are cutting prices.

Wintertime sluggishness has slowed luxury markets across the nation. Days on market have been increasing in nearly every major market tracked by the Institute for Luxury Home Marketing, and inventories are at a seasonal low, down from 27,600 properties in June to 18,400 in January.

Rather than falling with the end of the summer buying season, low inventories have placed upward pressure on prices, which have risen from a median of 1.11 million in September to 1.23 in January, according to ILHM data.

Perhaps as a result of strong prices, sellers are not responding as they normally do in the winter by cutting prices to generate interest among buyers. In fact, fewer are reducing prices today than when days on market were lower last summer.

The percentage of homes on the market that have lowered their asking price at least once over the past 90-day period has fallen 10 percentage points since the end of the summer, from 31.4 percent of properties to 24.4 percent. This statistic illustrates how many listed properties may be behind the “price curve” – listed at a price above what the market is willing to pay for similar properties. Even in strong seller’s markets, the percent price decreased will be 10-12 percent, so some repricing of individual properties is common in any market. In weaker markets, this value begins rise into the teens, 20 percent, 30 percent, and higher. Percent price decreased is an insightful gauge of demand levels in the residential housing market.

The National Association of Realtors reported that sales of luxury homes spiked in the final months of 2012 as high-end homeowners rushed to take advantage of lower tax rates before January 1.

Many sellers wanted to cash in on their homes before a widely expected capital gains hike — to 20 percent from 15 percent — that was part of the fiscal cliff budget deal. According to the National Association of Realtors (NAR), sales of homes valued at $1 million or more spiked 51% in November compared with a year earlier.