Left unmeasured, regulatory costs stop being just a transparency problem. Regulation protects financial institutions by reducing their exposure when something goes wrong. But complying with those rules also consumes resources every day: labour, capital and attention that firms could otherwise be holding in reserve. In good times, that drain shows up as slower growth; in bad times, it eats into the cushion institutions need to survive. Push it far enough without ever checking the toll and the arithmetic flips: past a certain point, more regulation can leave the system with less protection, not more, because the drain outweighs the gain.