“…Indeed, most previous studies reveal that women are more likely to make informal payments for health care services [6,40,42,46,59], as do younger persons [6,45,47,49,60], better educated persons [6,[40][41][42]47,49], those having a job [41], those married [49], those living in a smaller household [40,49,50], those living in rural areas [45,60,61], and those with lower income [31,37,57,61]. By testing this hypothesis, whether these populations also have a higher institutional asymmetry can be evaluated.…”