Alex receives a surprise tax refund of 500 dollars. That sam…

Alex receives a surprise tax refund of 500 dollars. That same week, Alex also discovers an error on a phone bill and owes an unexpected 500 dollars. In net terms, Alex is no better or worse off than before these two events. However, Alex feels significantly more upset about the unexpected bill than happy about the refund—and decides to pay the bill using money from a regular savings account rather than the tax refund, which Alex has already mentally labeled as “vacation money.” Which concepts from behavioral economics best explain Alex’s reaction?