NEW YORK ( TheStreet) -- Automatic-enrollment in 401(k) plans is a mom-and-apple-pie idea, supported by just about everyone from the president to academics who study retirement issues. But it turns out there's an unintended consequence: companies that adopt it often get stingier with matching contributions. That's the finding of a study by the Center for Retirement Research at Boston University. While auto-enrollment does benefit employees who otherwise wouldn't bother to participate in their firm's 401(k), lower matches hurt all the participants. The cuts in matching contributions are not big, just a fraction of a percentage point on average. But they show that companies pressed to adopt auto-enrollment could become reluctant to raise matching contributions, something many retirement experts would rather see.