FROM the earliest days of the credit crisis, the nation’s big financial institutions have been less than forthcoming about ballooning loan losses buried inside their books. To some degree this is understandable: denial is a powerful thing, after all, and writing off troubled loans during a period of severe stress is, for bankers, the equivalent of getting a root canal.

As profits rebound at many of these institutions, however, artful dodging becomes more disturbing. And when disguising problems winds up harming the taxpayer  the same folks who rode to the rescue of banks with billions of dollars  the denial is downright exasperating.

Among the more glaring bookkeeping fictions on big banks’ balance sheets today are the values they assign to all of the bounteous second mortgage loans. doled out during the mortgage bonanza. As any realist will attest, many of these loans are worth little, and yet there they sit, at fantasy levels, on banks’ ledgers.

Refusing to face reality on second liens ultimately hurts shareholders. But taxpayers are the ones holding the bag when institutions try to avoid losses by refusing to buy back problem loans they have sold to Fannie Mae and Freddie Mac, the mortgage finance giants that are wards of the state.