A gaggle of Wall Street bankers will be hauled before the Financial Crisis Inquiry Commission later this week. The topic: their role in blowing up the economy. CEOs from Goldman Sachs (NYSE:GS), Morgan Stanley (NYSE:MS), JPMorgan Chase (NYSE:JPM), and Bank of America (NYSE:BAC) will be the guests of honor, hosted by the panel appointed by Congress.

According to the commission's vice chairman, the inquiry is modeled to determine "what happened and not what should happen next." That's admirable. Perhaps you'll remember Congress's 2008 Big Oil flogging session that achieved precisely nothing. No one seemed to care why oil was rising -- just that it was, and that maniacally screaming at the bosses of ExxonMobil (NYSE:XOM) and ConocoPhillips (NYSE:COP) somehow eased the pain.   

But when asking how the financial crisis happened, and those answers aren't as obvious as many assume, what questions should be asked? Here are five I'd want the bankers to answer.

1. Most lay blame for the crisis on top-down issues like monetary policy. But some say ground-level issues like banning no-doc mortgages, ridiculous resets, and no-down-payment lending could have prevented the housing bubble hands down.

From your vantage point, are the roots of the crisis top-down, or bottom-up? Did macro factors alone drive the system off a cliff, or were deficiencies on your end simply juiced and exacerbated by faulty public policy?

Why ask? It's an important distinction to make. Banks don't want either side messed with, but I'd be interested to hear which factor is more to blame in their minds.

2. CNBC reporter David Faber begins a chapter of his book by writing, "There would have been no credit crisis and therefore no economic crisis if not for the complicity of the rating agencies."

Do you agree? If so, let me ask point-blank: Should NRSRO regulations be stripped away, ending the near-monopoly a few ratings agencies hold? If a more competitive, properly incentivized market for ratings existed, how would your securitization process have differed from where it was during the '04-'07 boom?

Why ask? Probably the most overlooked and underrecognized enabler of the fallout. I'd love for bankers to address the degree to which their own behavior was facilitated by the ratings agencies.

3. When I rent a house, I have to fully document my income, have my credit scrutinized, and put down a sizeable deposit. During the housing boom, you could buy a house with income pulled from your hindquarters, vaporized credit, and no money down. Does this seem backwards to you? Honestly, not to rub it in, but what logic were lending standards based on? Were truthful assumptions regrettably wrong, or was this a known game of hot potato?

Why ask: In hindsight, I'm curious whether bankers feel they were blinded by stupidity, or knowingly participating in a game of irresponsibility. Both are indefensible, but it's an important distinction to make.

4. Regarding securitization: Before you purchased individual loans from mortgage originators, was someone dispatched to the ground, questioning, viewing, and verifying the loans' quality? In other words, did you have any idea what was inside the collateralized debt obligations you were selling, or was this just a game of blind trust and "buyer beware?"

Why ask? In most cases, the answer is probably no. Banks were like real estate agents selling homes they had never seen and couldn't verify existed, and that may or may not have resembled the three-bedroom, two-bath model they had advertised.

Understanding how the acquisition process works is key to addressing the erosion of lending standards. One solution is forcing banks to keep part of the loans they sell -- including those to Fannie Mae (NYSE:FNM) and Freddie Mac -- on their own books for good. Then watch how quickly banks become concerned about underwriting standards.

5. At one point or another, many of your banks were leveraged at, near, or above 30 to 1. This means asset price declines of just over 3% leave you six feet under. Simple math.

Now, you didn't really believe a 3% decline was impossible, or even unlikely, did you? You aren't stupid people. You had to know that at some point either asset sales, capital raising, or nuclear armageddon was inevitable, right?

Why ask? Confronted with these simple facts, it's hard to answer without either saying (a) yes, I'm a nimrod and had no idea what I was doing, or (b) you're right, I saw trouble lurking, but saddled up and hung on because my pay was based on short-term profits I couldn't resist.

Prying out truthful answers to this question will no doubt confirm former Morgan Stanley CEO John Mack's confession that bankers "cannot control ourselves" and that "regulators have to be much more involved."

Your turn to fire away
What would you ask the bankers this week, Fools? Share your thoughts in the comments section below.

Fool contributor Morgan Housel doesn't own shares in any of the companies mentioned in this article. The Fool has a disclosure policy.