The insurance companies are playing a form of iterated prisoner's dilemma against each other. If one company made itself highly transparent, it would gain business at the expense of all the opaque companies; but the opaque companies would follow suit, leading to a new equilibrium in which the industry as a whole made less money, but apportioned in the same way. Additionally, disclosing the contents of their price-setting black boxes would make it easier for new companies to construct similar boxes, and become competition.