What is really going on? It is true that, starting in 2013, the new law eliminates a corporate tax advantage on retiree drug benefits that amounts to double-dipping.

It is also true that accounting rules require that the present value of the entire additional tax that companies will have to pay over the next several decades be put on the books now. That led AT&T to declare a charge of about $1 billion in the first quarter of 2010 and Verizon to declare $970 million.

Those look like staggering amounts until one understands that they don’t require any immediate cash payments and that the added taxes will be paid out slowly — over perhaps 30, 40 or more years, depending on a company’s retiree plan.

Wall Street certainly gave a collective yawn. Stock prices for the companies that made announcements barely budged (some went up), and analysts urged investors not to overreact because the accounting change would have a negligible impact on these companies’ valuation, or market capitalization. More from The New York Times here.