If "support" means statistics, then no, there is no valid support. All I can offer is logic. For example: https://en.wikipedia.org/wiki/Marginal_revenue_productivity_...

Is this (https://saylordotorg.github.io/text_principles-of-economics-...) hard to understand?

Or maybe you want something more rigorous: https://mises.org/library/theory-idle-resources-0