Well, this should come as no surprise, but it's confirmed that bosses prefer overconfidence to accuracy when asked for estimations.
I've spoken before about how I personally prefer Truth over Harmony, with estimation as a prime example. Mainly because, when it turns out that an estimate was inaccurate... you know who's going to get the blame for "coming in late".
And yet I've found in the past that if I try for accuracy, the truth is taken as "pessimism" (by comparison with the overconfident, optimistic estimates given by others).
What I found particularly scary (and accurate) was the final quote of the article:
"Thus bosses of software managers take accurate estimates to be a signal of a lack of competence."
This is not how the world should work :(