Several years ago, I recommended two stocks in The Oxford Income Letter that generated a lot of reader feedback. I suggested that readers buy stock of a tobacco company that has since been acquired and GEO Group (NYSE: GEO), a private prison operator.

Nearly all of the emails I received about those two stocks were from people angry that I would recommend companies that they considered immoral.

I reminded them that my job is not to impart my values or anyone else’s but to find the best investments I possibly could. It would then be up to each individual to determine whether it was a good fit for them.

These days, more investors are considering their values when investing. That’s why ESG investing has become so popular. ESG stands for environmental, social and governance. The idea is to invest in companies that treat the environment, customers, and employees well.

Assets under management in socially responsible investing strategies are up 25% in four years to $22.9 trillion. That’s trillion, with a “t”. So don’t think that ESG investing is only for tree huggers or your hippie brother-in-law.

And this type of investing is working.

In a study of stock performance from 1982 to 2017, Research Affiliates found that removing stocks that don’t fit into the ESG model has little impact on performance. For example, eliminating fossil fuels from the RAFI U.S. Index improved annual performance by 16 basis points (a basis point is one-hundredth of a percentage point). Removing tobacco led to an underperformance of just eight basis points.

Research Affiliates found similar results in markets outside the U.S.

Dr. Kristin Hull, founder, CEO, and CIO of Nia Impact Capital, whose goal is to “design portfolios where financial performance and social impact work hand in hand”, is a leader in socially responsible investing.

She told me, “I find huge opportunities in solving for our earth’s greatest risks, from healthcare to tropical disease, to sustainable energy issues, to financial inclusion, etc”.