Campbell, Donald T. Assessing the impact of planned social change. Evaluation and Program Planning. 1979, 2 (1): 67–90. doi:10.1016/0149-7189(79)90048-X.
(p. 85)原文:"The more any quantitative social indicator(英语:social indicator) is used for social decision-making, the more subject it will be to corruption pressures and the more apt it will be to distort and corrupt the social processes it is intended to monitor."