ABSTRACT Greenberg (1980) assumed that the magnitude of indebtedness was an additive function of the recipient's benefits(B) from the aid and the donor's costs(C). This relationship is expressed by the equation I = x1B + x2C, where xl and x2 are empirically determined weights and xl > x2. The first purpose of this study was to examine the validity of this equation in Japanese society; the second was to give weights to each of 20 determinants of the magnitude of indebtedness. Japanese students and adults (N = 302) were asked to recall experiences of receiving help and to answer a series of questions regarding their reactions to those experiences. Multiple regression analyses indicated that the equation was valid for real help-receiving situations in Japanese society, but xl was not greater than x2. Hayashi's (1974) quantification method indicated that the following factors had impact on the magnitude of indebtedness: the donor's cost, the recipient's affection after receiving aid, the reason why the recipi...