Is Tesla or Exxon More Sustainable? It Depends Whom You Ask

As investors back more companies based on social factors, questions arise about how to grade them

Is Elon Musk’s electric-car maker Tesla the best, the worst or a merely middling performer on environmental issues? Is Warren Buffett’s Berkshire Hathaway one of the worst-governed big U.S. companies? Is General Motors one of the most socially aware businesses, or one of the least?

Investors picking a scoring system for ESG – environmental, social and governance – issues facing companies can have any of those outcomes.

The...