The issue of preference interdependence between individuals has attracted increasing dis- cussion. However, the e ects of di erent sources of preference interdependence cannot be separately estimated because of the simultaneity problem. One approach to solving this simultaneity problem is to make use of partial-population experiment. This paper makes use of the disaster experiment of the Taiwan earthquake in 1999 to empirically estimate the e ects of di erent sources of preference interdependence in charitable giving. The results reveal that the endogenous e ect of others' contributions is signi cantly positive and the exogenous e ect of others' incomes is signi cantly negative. The results suggest that households' decisions on their contributions are in uenced by others' contributions and incomes. The existence of the endogenous e ect is thus able to provide an alternative explanation for the di erence in charitable giving between Taiwan and the US. The price elasticity and the income elasticity of charitable giving are also estimated. While the estimates of price elasticity are larger than those based on the US data, they are similar in magnitude to previous estimates based on the data from Singapore and Taiwan.