The issue of corporate political contributions has drawn a lot of attention since 2010, when the Supreme Court opened the way for secret political contributions by companies and unions. Shareholder groups are pressing businesses to disclose what they give and warning of the risks involved in making contributions, including damage to corporate reputations, extortion and waste of corporate assets. The response from companies has been mixed. Now two organizations have made an effort to assess how much corporations are revealing about such contributions. An index from Baruch College in New York rates S&P 100 companies on the extent of their disclosures and their policies regarding contributions.

The Baruch index shows 22% of S&P 100 companies disclose little or no information about political expenditures, with the companies that give the most disclosing less than others.

The Center for Political Accountability (CPA) put together another index of S&P 100 companies in conjunction with the Zicklin Center for Business Ethics at the Wharton School. That index shows that one-third have some limits on corporate political spending, and almost one in four are not contributing directly to political campaigns. Fifty-seven of the companies disclose direct corporate political spending and have adopted board oversight, the CPA says.