The social sciences also have a much more limited ability to perform controlled experiments because of ethical reasons, which cannot be resolved with more money

The social sciences also have a much more limited ability to perform controlled experiments because of ethical reasons, which cannot be resolved with more money. So much of the studies published in these fields are observational rather than controlled experiments. Physics (and chemistry, to a lesser extent biology, and medicine lesser still) has an advantage in that it's exploring the parts of the universe where controlled experiments are possible. I don't think it's all about resources, and I think the social sciences are less resourced in part because grant-making bodies know that these fields suffer from these intrinsic limitations.