The endowment effect is the finding that possession of an item adds to its value. We introduce a new procedure for testing this effect: participants are divided into two groups. Possession group participants inspect a numbered lottery ticket and know it is theirs, while inspection group...

The diversification bias in repeated lotteries is the finding that a majority of participants fail to select the option offering the highest probability. This phenomenon is systematic and immune to classical manipulations (e.g. monetary rewards). We apply dual process theories and argue that the...