I disagree. "Pro-forma" is quite recent as a common way to report earnings. In the past it was reserved for unusual situations like mergers or highly unusual charges or gains against earnings. Now it is used every quarter for most every company and the "one time charges" are a complete joke that recur every quarter and exclude even a lot of common operating expenses. The now common practice of charging off inventory (an excluded "one time charge") one quarter then selling it the next quarter using a zero cost basis (100% profit margin) is both very new and getting very common among tech companies. It is also a fraud against the stockholders, in my opinion.
No, historical comparisons are only valid if you use GAAP earnings.
If we changed that then all our historical databases on valuations will be out of whack.
what!?!
if i pick up s&p reports on a stock and its history, its all gaap earnings, or something standard. the "historical database" of earnings doesn't remember pro forma. its only being used in this game of "beat the analysts' concensus". well, maybe except for amazon.
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