Gas prices were surely a factor. But major reason was the leveraged derivatives issued by banks which collapsed when housing bubble burst. Banks were rescued by TARP, courtesy of tax payers. Too bad the TARP does not rescue me when my investments decline.
You’re looking at it MACRO, I am looking at it MICRO. Why did the housing bubble burst? I think that it had a lot do with people getting homes they could barely afford. When something changed, spike in gas price and the attendant rise in food prices, many of the people just defaulted. It started to snowball when people started to lose their jobs also. Yes, it was due to derivatives but many of these investments relied on stability in the housing market and all that started to fall apart when over indebted people stopped making payments. So irresponsible banks lending to irresponsible people begat the crash. It was a house of cards built on greed by all parties, big-shots and little-shots who wanted to live beyond their means.