It's relative not absolute rates that matter.  Canada's ranking in the OECD for corporate taxes barely budged as other countries cut theirs by similar amounts.  Otherwise had we not cut them we would have done even worse.  As for tax cuts for the rich it's about the optimal point.  If too high, they can work very well like when Kennedy cut the top rate from 91% to 70%, Reagan from 70% to 50% and again from 50% to 28%, however Clinton and Obama's rise to 39.6% didn't hurt the US and Bush's tax cut to 35% didn't help so it depends where you are relative to the optimal level.  Our combined top rate in BC is 47.7% which is either at or slightly above the optimal level, but not quite as bad as some other provinces.