Jim Cramer frequently talks about the importance of flexibility in investing: as he paraphrases John Kerry, you have to be "Willing to vote for a stock...before you vote against it." However, saying that you had a different opinion on a stock after the fact isn't being flexible: It's lying. It's the Wall Street equivalent of saying you knew the Red Sox were gonna pull it off down 3-0 in the 2004 American League Division Series.

Yet according to research by Alexander Ljungqvist, Christopher Malloy, and Felicia Marston, it appears that analysts may be doing just that: changing their sentiment retroactively to appear more prescient than they really were:

Comparing two snapshots of the entire historical I/B/E/S database of research analyst stock recommendations, taken in 2002 and 2004 but each covering the same time period 1993-2002, we identify tens of thousands of changes which collectively call into question the principle of replicability of empirical research. The changes are of four types: 1) The non-random removal of 19,904 analyst names from historic recommendations ("anonymizations"); 2) the addition of 19,204 new records that were not previously part of the database; 3) the removal of 4,923 records that had been in the data; and 4) alterations to 10,698 historical recommendation levels. In total, we document 54,729 ex post changes to a database originally containing 280,463 observations.