FRED keeps adding new data.* The latest batch is detailed data on the housing market from Realtor.com. The FRED graph above shows the well-known seasonal pattern in the number of properties actively on sale: The real estate market is much thinner in the winter, and sellers often wait for spring to put their properties up for sale.

But not everyone can wait. Financial circumstances, job-related moves, or new family situations may force an owner to put a house up for sale at a moment that’s not optimal. On the other side of the market, job or family circumstances may force some people to look for a house when it’s not the best time to do so.

It turns out the first story is more common: that is, too many sellers chasing too few buyers (at least in relative terms). This imbalance leads to lower prices in the winter, as we can see in the graph below.

*Today, FRED has over 763,000 U.S. and international time series from 94 sources.

How these graphs were created: Search FRED for “Housing inventory” and click on the series you want displayed. Both series shown here should be in the first page of results.

Suggested by Christian Zimmermann.