A study in 2014 by Kessler and Roth analyzed the impact of California's attempt to increase the rate at which people sign up to be organ donors. Most states in the United States are opt-in, that is, you are not an organ donor by default, but can choose to opt in when getting your driver's license. Compared to other countries around the world that have an opt out policy, where you are assumed to be an organ donor by default and choose not to be one, the rates are expectedly much lower. The last option is called "active choice", where you must select whether or not you choose to be a dono