The result was a financial industry that was hugely profitable as long as housing prices were going up — finance accounted for more than a third of total U.S. profits as the bubble was inflating — but was brought to the edge of collapse once the bubble burst. It took government aid on an immense scale, and the promise of even more aid if needed, to pull the industry back from the brink. And here’s the thing: Since that aid came with few strings — in particular, no major banks were nationalized even though some clearly wouldn’t have survived without government help — there’s every incentive for bankers to engage in a repeat performance. After all, it’s now clear that they’re living in a heads-they-win, tails-taxpayers-lose world.