Home values are increasing and most of the time that should be a huge incentive for people (including homebuilders) to put houses on the market and either upgrade or downgrade and save money. But that’s not happening. Instead, homebuyers are being picky and continue to compete for hard-to-find homes for sale.

U.S. home prices rose 5.4 percent in December, the largest year-over-year gain since July 2014. The median sales price of a previously owned home also jumped 8.2 percent from last January, the largest year-over-year gain since April 2015 and the 47th straight month of increases.

While the number of existing homes on the market at the end of January increased from December, the level was still 2.2 percent lower than a year ago.

Here’s hoping the warm weather of Spring inspires more people to buy.

So why are there fewer homes for sale?

1. Not as many new homes.

While the pace of new household formation has recovered from lows during the recession, homebuilding has not kept up. There simply have not been as many homes built as in years past.

2. Fewer distressed properties.

After the housing bubble burst, there was a glut of distressed properties on the market, either in foreclosure or up for sale by desperate homeowners willing to sell them for less than they owed on their mortgage. The number of distressed properties has fallen drastically since.

The other reason comes with the prices of homes rising, there is no incentive for a bank or lender to approve a short sale to a homeowner who wants to get out a property. There’s just not any reason that makes sense in the current economy.

3. Fewer job relocations.

Job relocation was the second-highest reason that home sellers sold their previous home last year. As people settle down and put in roots, there is less of a reason to move to a new city or new state.

4. Staying put in the golden years.

While plenty of seniors plan to downsize, a good portion of baby boomers don’t intend to move. It just does not make sense for them. In some cases, children might have moved back home and are helping with bills and mortgage payments.

5. Stuck homeowners.

More than half of home buyers last year used proceeds from the sale of their previous home to purchase a new house. The median equity sellers got out of their old home was 23 percent. But for many current homeowners, that is not an option anymore. They simply can’t sell their homes because there is not enough equity.

Just over one in six of the approximately 50 million homes with a mortgage have less than 20 percent equity in them, according to CoreLogic. About 4.1 million homes, or 8.1 percent, are worth less than their mortgage and would require a seller to bring money to the closing table to settle the home loan. That’s enough reason to keep many people from selling their homes it just does not make sense financially.

6. Lack of Inventory

For those homeowners who do want to sell and see rising prices as an opportunity to get a good return on their property, the very reason they may not be selling is because of the lack of inventory. If there are not any homes that meet your needs, you just won’t be motivated to buy or even look for a home.