I don't know how scientific the study is, but it would appear confirm something I have long suspected -- that arguments are generally a waste of time.

Yeah, my experience, admittedly anecdotal, is that no one changes their mind in an argument. I cannot recall ever having seen it happen.

"Is there any way to debunk anything so that it stays debunked?"

Only when the believer pays some natural cost for believing lies. And even that's not foolproof.

We are made of poor stuff, aren't we? We understand logic but cannot make ourselves logical; understand goodness but cannot be good.

wow, you mean like falsely blaming the CRA for the sub-prime mortgage crisis?

The fault lies with the small army of hard left political hustlers who spent the early 1990s pushing risky mortgages on home lenders. And the fault lies especially with the legislators that gave them the power to do it.

As noted below, what a load of crap (which is the null hypothesis, or better, the exceptionally strong prior, whenever you see anything with byline on the article above). Here's Ezra Klein:

The new line we're hearing is that the financial meltdown was really the product of the Community Reinvestment Act, a piece of legislation from the late-70s that required federally-insured banks to lend throughout the areas from which they take deposits, including poor neighborhoods, which were being systematically excluded from credit. The legislation, by all accounts, worked. Now, however, conservatives are trying to argue that it's behind the crisis: If the CRA hadn't been pushing these banks to make all these unsafe loans, then the birds would still sing...

As Robert Gordon shows, however, this is crap. First, there's the timing. CRA came in 1977. The crisis came in 2007. Indeed, by 2004, the Bush administration had weakened the CRA -- and after that (though not, presumably, because of it), bubble lending really took off. Further, CRA only governs a certain class of federally insured banks. Problem is, half of the subprime loans came from mortgage companies with no CRA involvement at all. Another 25%-30% came from companies with very little CRA exposure. For those who left their abacus at home, that's 80% of the loans which were fully or largely outside CRA jurisdiction. More than that, the non-CRA mortgage firms made subprime loans at twice the rate of CRA-covered firms. Which basically leaves a stake in the heart of this particular theory. Indeed, until now, some conservatives have been moaning that no one is talking about the CRA part because it's so racially charged. Poppycock. It's just a false charge...

Ezra didn't cover the change in 1995, except indirectly by noting the timing of the crisis, but for completeness, here's Robert Gordon. He also covers why the merger argument is flawed:

In the mid-1990s, new CRA regulations and a wave of mergers led to a flurry of CRA activity, but, as noted by the New America Foundation's Ellen Seidman (and by Harvard's Joint Center), that activity "largely came to an end by 2001." In late 2004, the Bush administration announced plans to sharply weaken CRA regulations, pulling small and mid-sized banks out from under the law's toughest standards. Yet sub-prime lending continued, and even intensified -- at the very time when activity under CRA had slowed and the law had weakened...

The real agenda behind this shameless push to blame the CRA is evident.

I suppose this is when I say, "Yes, dear."?

"The real agenda behind this shameless push to blame the CRA is evident?"

Real agenda? What might that be?

I did not blame the CRA (which was revised several times, by the way), but the abandonment of standards. The problem is bad loans, and Fannie Mae and Freddie Mac. Whether they were issued by banks covered by the CRA is irrelevant. Loans in excess of 80% of FMV, or to persons with bad credit or insufficient income should never have been made -- whether by CRA-covered banks or otherwise.

What's the agenda of a comment like the above?

Mark Thoma, eh?

http://economistsview.typepad.com/economistsview/2008/04/yet-again-it-wa.html

If you really are serious about the question, pay close attention to the anthropomorphic global warming cult. The wheels have been coming off that bandwagon for over a year now, and their repsonse has been to ratchet up the shrill hysteria.

You could also look into the flying saucer people, among whom it is impossible to debunk any of their cherished myths. Demolish one, and they pull out another. Dmeolish it, and another one pops up. Keep going, and eventually they trot out - the first one you dmeolished, triumphantly asking "Well, what about THIS one, huh?"

Some folks are just permanently stupid.