The law of unintended consequences was popularized in 1936 by American sociologist Robert K. Merton. It is defined as unintended consequences are the outcomes that are not the ones foreseen and intended by a purposeful action.
The state of California and the plumbing industry found one of these recently. According to a Los Angeles Times report, thanks to California Gov. Jerry Brown’s call in 2015 — as the state was in the middle of a four-year drought — for his constituents to reduce their water usage by 25%, the Golden State saved massive amounts of energy.