I'm often asked why are there so few home available to purchase here in the Seattle area. There are many reasons but here are some on the main ones.
1. Economy - the Seattle economy is doing very well making it a very good time for residence to buy. Its also drawing in new people every month, moving here to get in on our good fortune.
2. A New Baby Boom - the Millennial generation is huge and they are just now starting to reach the typically age that people purchase their first home. This echo of the Baby Boomer generation is doing the same thing that generation did in the 60's and 70's.
3. Loan Eligible Again - almost all of the home owners that went through short sales and foreclosures during the Housing Bust are now loan eligible again. As a matter of pride many of them want to get back into home ownership.
4. Slow Development - During and after the Housing Bust most developers, builders and lenders were very skittish about building too quickly or at all. Many that survived the Bust are still licking their wounds while so many others didn't make it. Although development had returned it take a long time to get that manufacturing engine really humming again. Lending for new construction development has still been a huge set back as most small builders are having to borrow from high interest private lenders.
5. Fear of the Market - I talk to home owners all the time that would love to move to downsize or buy into a different location. They know that the current market conditions are ideal to sell, but they fear having to become one of the masses trying to buy a new home. So they are sitting on the sidelines and deciding to stay put rather than making their home available for purchase.
Here is a great synopsis article writing but he National Association of Realtors if you'd like to read more about reasons why there is a supply shortage of homes.
http://realtormag.realtor.org/daily-news/2016/03/23/6-ways-explain-low-inventory