SAN FRANCISCO (KCBS) — Getting started in the housing market is harder than ever for many Americans, wherever they try to buy, and new data shows that starter home inventory is down significantly over the past few years.

Real estate firm Trulia finds that starter home inventory is down overall by more than 40 percent since 2012, and in the Bay Area, investors are holding onto a large percentage of those homes.

“A large share of starter homes that could be on the market are actually owned by investors in the Bay Area – that hovers around 40 percent; nationally it’s about 31 percent. These are homes that were likely foreclosed upon during the financial crisis, bought up by investors and turned into rental units,” Ralph McLaughlin, Chief Economist for Trulia told KCBS.

The second reason for the low inventory, according to McLaughlin is that “Prices of premium homes have actually started to grow further and further out of reach, so if you own a trade-up home, and say you want to buy and move up to a premium home, it’s much more difficult to do so, just because it’s more expensive.”

In the Bay Area, the median price of the homes that normally attract first-time buyers is higher than anywhere in the nation.

“The shocking number that came out of the report was actually the share of income the starter home buyer, even if they can put 20 percent down on a home, would have to spend to service the mortgage, is like 110 percent of their income. That’s unbelievable. That’s uncharacteristic of the rest of the country, but that really is a sign that home-seekers are starting to look down the housing ladder,” McLaughlin said.