Investment Model Scale
Rusbult, C. E., Martz, J. M., & Agnew, C. R. (1998). The investment model scale: Measuring commitment level, satisfaction level, quality of alternatives, and investment size. Personal Relationships, 5 (4), 357-387. https://doi.org/10.1111/j.1475-6811.1998.tb00177.x
The Investment Model Scale is designed to measure four constructs, including commitment level and three bases of dependence: satisfaction level, quality of alternatives, and investment size.