Those with big stakes in the housing industry appear to be champing at the bit to declare the recession over and recovery just around the corner.

Not as convinced are economists and observers outside the industry, who do not see a few months of comparatively positive sales and construction numbers as a guarantee that the worst is behind us.

Several reasons appear consistently in the skeptics' analyses: the tax credit for first-time buyers, interest-rate volatility, government intervention, continuing unemployment, and the steady stream of foreclosures and mortgage delinquencies nationwide.

In interviews, more than two dozen economists and experts elaborated on these points.

The $8,000 tax credit. Thus far, 370,000 home sales to qualified first-time buyers are attributed to this. But the incentive expires Nov. 30. Congressional leaders have pledged to extend it. The housing industry wants it extended, and expanded.

"The tax credit has clearly had a positive effect on housing demand," said Joe Robson, the National Association of Home Builders' chairman.

But some others said that, like "Cash for Clunkers," the credit is merely tapping pent-up demand.

"If all you have done is shifted home purchases that would have occurred anyway from the future into the present, that is simply moving home sales around rather than increasing their overall level," said economist Kevin Gillen, vice president of Econsult Corp. in Philadelphia.

Interest rates. Thirty-year fixed-rate mortgages are down to 4.87 percent. Rates tend to be volatile, however, and first-time buyers keep an especially close watch.

Brian Bethune at IHS Global Insight Inc. said of the rates: "There will be some gradual decline, but they are pretty much in place now."

Bankrate.com columnist Holden Lewis says he believes they will increase "simply because they're so low" now: "The 30-year fixed is near historic lows, which means that it has been higher than this almost every day in the last several decades, so it seems natural that it will rise."

Bethune, Lewis, and Mark Zandi, of Moody's Economy.com, all prominently mentioned the Fed's decision to stop buying Fannie Mae and Freddie Mac loans and mortgage-backed securities in March as one reason rates will not fall much more.

If the Fed slows purchases before then, rates may rise because investors will have to take up the slack, and they'll demand higher rates to "compensate for the perceived risk," Lewis said.

The housing market, Zandi said, "is showing improvement only because it is on government life support."

Though rates for conventional home loans are low, both the cost and requirements for "jumbo" mortgages - those above $417,000 - remain high and tight.

And though the Fed and the Treasury Department have thrown money and guarantees at lenders to get them to pry open their wallets to consumers and the housing industry, builders are dipping more deeply into their own purses, or not building at all.

Said the Home Builders Association's Robson, "There can be no meaningful economic recovery until the flow of credit is restored to housing."

Government intervention. With housing, the government is seen as both a solution and a problem.

On the one hand is real estate industry consultant John Burns' assessment: "Government intervention to date has been extremely helpful in preventing an even more dramatic decline in home prices."

On the other hand, in a report issued last week, the Congressional Oversight Panel monitoring the Obama administration's loan-tweaking Home Affordable Mortgage Program (HAMP) said it was focusing on the housing crisis "as it existed six months ago," when it was dealing with the fallout of the subprime loans, rather than addressing payment delinquencies caused by unemployment.