Moral Licensing
A similar phenomenon has been studied in the lab by psychologists. It’s called moral licensing: the idea that doing one good action leads one to compensate by doing fewer good actions in the future.
What happened? People who had previously purchased a green product were significantly more likely to both lie and steal than those who had purchased the conventional product. Their demonstration of ethical behavior subconsciously gave them license to act unethically when the chance arose.
.. Cannibalism of funding among charities is a major problem. However, there is a solution. The moral licensing phenomenon doesn’t always happen: there is a countervailing psychological force, called commitment effects. If in donating to charity you don’t conceive of it as “doing your bit” but instead as taking one small step towards making altruism a part of your identity, then one good deed really will beget another. This means that we should tie new altruistic commitments to serious, long-lasting behavior change. Rather than making a small donation to a charity you’ve barely heard of, you could make a commitment to find out which charities are most cost-effective, and to set up an ongoing commitment to those charities that you conclude do the most good with your donations. Or you could publicly pledge to givea proportion of your income.