In December, I wrote to the heads of six of the country’s biggest financial institutions with a simple request: that they voluntarily disclose the financial contributions their companies make to think tanks. This disclosure would help make sure shareholders, policymakers, and the public are aware of efforts by large Wall Street banks to indirectly influence lawmakers and regulators by supporting think tanks’ research. Unfortunately, none of the six institutions — JPMorgan Chase, Bank of America, Citigroup, Wells Fargo, Goldman Sachs, and Morgan Stanley — has agreed to release this information.