Charles Green of Trusted Advisor Associates, an HBS alum, finds himself surprised by the number of MBAs who have signed the oath.

Well, shame on me, o me of little faith in my descendant classmates, because as of June 3 (according to the Economist’s story), that number was up to 400—roughly half, by my close-enough calculations. Now, half is considerably larger than 20%. In fact, I think it’s more like 50%, though HBS MBAs in my day weren’t all that great at math (‘go hire one from MIT if you need it’ was the not-so-tongue-in-cheek phrase we heard). And I am quite sure, as I mentally run down my list of classmates, that nowhere near 50% would have signed the oath back in the day […] Good for you, HBS class of 2009. I say you done us proud.

We thank Mr. Green and also note that MBA alums of prior years are also taking the oath.