The Good Samaritan and Traffic on the Road to Jericho
研究了志愿者困境的一个变体：人们依次看到有人遇险并决定是否帮助。发现当潜在帮助者出现频率超过阈值时，个体帮助概率下降但期望等待时间恒定；若帮助成本不同，则期望等待时间随频率增加而减少。
This paper studies a version of the Volunteer's Dilemma in which players sequentially observe someone in trouble and decide whether to help. Where preferences are identical, we show that if the frequency with which potential helpers appear is above some threshold, then as frequency of appearance increases, the probability that any individual stops diminishes, but the expected waiting time for help to appear is constant. Where costs of stopping differ among individuals, as the frequency of appearance increases, the expected waiting time for help to appear decreases, even though the probability that any individual stops diminishes.