I'll ask the same question I've asked elsewhere because "I want to believe:" How do you measure how much someone has made the world a better place? Especially when so much of their actions, their consequences, and their second and third order effects are either unknowable or papered over by PR campaigns.

You can't really measure how much good someone has done, but their foundation has been going for 25 years and as mentioned in the article they've donated 100billion dollars to something already.

If anyone deserves a bit of good faith it'd be the Gates family, it's probably not all pretty and perfect but I am convinced they're doing a lot of good.

You'll have to ask someone else about proof, but I imagine someone would've leaked something within these 25 years if they were running a tax evasion scheme or something else fishy.

So without hard proof I repeat: Let Bill have his toys, it's a piss in the bucket on a global scale and the donated 100 billion dollars will have offset that in some way or another many times over.

Let's just say my "sniff test" says good, and while not always right I think I am here and that's good enough for me.

I don't think you can. I think the best we have is intention and Gates seems to have good intentions to me.