The hidden side of everything

I follow @freakonomics on Twitter. You may have read the book, but if not, it's basically an alternative take on economics and social issues - e.g did crime drop dramatically in New York because of the 'zero tolerance' policies adopted by the city Mayor, or was it because Roe-v-Wade had made abortion more easily available a couple of decades earlier? Their strapline is "The Hidden Side of Everything". So here's one of their latest tweets for starters... Discuss!

Did Celebrating Earth Day Make You Pollute More?
By Freakonomics.
Beware moral self-regulation. Doing good works, it turns out, may make people feel justified in doing ill. A new study from psychologists at Northwestern University suggests that “affirming a moral identity leads people to feel licensed to act immorally.” In other words, as Ryan Sager points out, acting green one day might leave you more willing to indulge your planet-destroying consumption impulses the next.