SILVER SPRING, Md.—The number of Americans who signed contracts to buy homes declined slightly for the fourth straight month, but it was still a record high for December. The National Association of Realtors’ index of pending home sales dipped 0.3 percent to 125.5 in December, an all-time high, according to the Friday report. An index of 100 represents the level of contract activity in 2001. Contract signings last month rose 21.4 percent over December 2019. Contract signings are considered a barometer of purchases that will take place the next one to two months. While it’s not always completely accurate, Friday’s report would suggest a strong winter for the housing market. Regionally, contract signings were essentially flat in the West and South, while they declined 3.6 percent in the Midwest. Signings rose 3.1 percent in the Northeast. Thanks to a sizzling summer that continued into fall, the housing market has largely …