Instead of studying the material. In a Monday Wall Street Journal op-ed, Michael Faulkender and Tyler Goodspeed, University of Maryland Finance Professor and Fellow at Stanford University’s Hoover Institution, respectively, wrote about bank stress tests and their resulting uniformity of banks’ risk management techniques. Citing a Boston Federal Reserve study, they noted that

banks that performed poorly on the mandated Dodd-Frank stress tests subsequently adjusted their portfolios such that they more closely resembled the portfolios of banks that performed well. The average institution’s portfolio is more diversified, but the system is more uniform. By requiring all of the biggest financial institutions to adhere to the same measures, pass the same tests, and follow the same practices, America has lost diversification in the entire banking sector.

Dodd-Frank, in essence, required individual banks to do better at diversifying their individual portfolios. But that business of all of them having to pass the same test means that all the banks have much the same portfolios, diversified over much the same instruments.

This is the complement of teaching the test rather than teaching the material and then testing that knowledge. Banks are (regulatorily pushed into) learning the test rather than learning the material and then acing the test.

Uniformity is dangerous for species in a biological ecology, and uniformity is dangerous for categories of businesses in an economical ecology.