本稿では、相続慣行、遺産動機の強さと性質、遺産の分配方法、他人に対し 経済的援助をする意思があるか否かに関するデータや様々な計量分析の結果を 概観し、どの家計行動の理論モデルが日本およびアメリカにおいて成り立って いるかについて吟味する。その結果、日本においてもアメリカにおいても利己 主義を前提としたライフ・サイクル・モデルが最も適用度が高いが、日本の場 合のほうがこのモデル（ および王朝モデル） の適用度がはるかに高く、逆にア メリカの場合のほうが利他主義モデルの適用度がはるかに高いということが分 かる｡

In this paper, I analyze a variety of data for Japan and, where available, for the United States on bequest practices, on the importance and nature of bequest motives, on bequest division, and on the willingness of individuals to help others and survey a variety of econometric analyses in order to determine which theoretical model of household behavior applies in the two countries. My results suggest that all three models (the life cycle, altruism, and dynasty models) coexist in both countries, that the selfish life cycle model is the most applicable model in both countries but that it is far more applicable in Japan than it is in the U.S., that the dynasty model is also more applicable in Japan than it is in the U.S. but that it is not of dominant importance even in Japan, and conversely, that the altruism model is far more applicable in the U.S. than it is in Japan. In the concluding section of the paper, I consider the policy implications of my findings.