In game theory, and particularly mechanism design, participation constraints or individual rationality constraints are said to be satisfied if a mechanism leaves all participants at least as well-off as they would have been if they hadn't participated.
ɪn ɡˈeɪm θˈiəɹi, ænd pɚtˈɪkjʊlɚli mˈɛkənˌɪzəm dɪzˈaɪn, pɑːɹtˈɪsɪpˈeɪʃən kənstɹˈeɪnts ɔːɹ ˌɪndᵻvˈɪdʒuːəl ɹˌæʃənˈælᵻɾi kənstɹˈeɪnts ɑːɹ sˈɛd təbi sˈæɾɪsfˌaɪd ɪf ɐ mˈɛkənˌɪzəm lˈiːvz ˈɔːl pɑːɹtˈɪsɪpənts æt lˈiːst æz wˈɛlˈɔf æz ðeɪ wʊdhɐv bˌɪn ɪf ðeɪ hˈædənt pɑːɹtˈɪsᵻpˌeɪɾᵻd.