[axelroze]

If I had $750m (or any more sizable wealth really, even 10m would be enough for where I live), would be to improve wealth inequality from the roots via the boring and slow route. Better education for children (equipment, teachers, etc), regular food on the table (big problem for many people), counselings and medicine for abusive parents.

Second best thing IMO would be to start some business which is sustainable and doing some social good. For example making e-readers and cheap e-books for the aforementioned children such that their parents can actually buy them. Side note: e-readers are discounted even today (selling at loss) and most money comes from e-Book sales.