Default effect (psychology)

Amongst the set of options that agents choose from, the default option is the option the chooser will obtain if she does nothing. Less conservative interpretations of default options include options that are normative or suggested. Experiments and observational studies show that making an option a default increases the likelihood that it is chosen; this is called the default effect. Different causes for this effect have been discussed. Setting or changing defaults therefore has been proposed as an effective way of influencing behavior—for example, with respect to deciding whether to become an organ donor, giving consent to receive e-mail marketing, or choosing the level of one’s retirement contributions.