Comment by dbrueck

Honestly, most companies have a net positive impact in the world, and if you live in a first world country and are interested in improving the world, one of the most effective ways to do that is make a lot of money and give a lot of it to well-run charities.

But if you want to specifically also work with a company with a "good cause", I'd strongly recommend that you go with a company whose entire mission is focused on a particular cause, as opposed to a more traditional company that says part of its mission is to "do good" or whatever. So, for example, Solar Cookers International could (maybe?) be an example of the former, while General Electric is the latter.

That's not to say GE is in any way bad, but if you want a do-good company and it's not a do-good company first and foremost, then at some point you will likely feel let down by it (or by yourself for working there). Also, it seems that a lot of normal for-profit companies that want to be seen as do-good companies can't help but get mired in politics (usually due to grossly oversimplifying complex social issues).