Previously I said that one of the reasons people don’t stick to resolutions is that the resolution is too much at once. The simple economic explanation is that the marginal effect of one “unit” of effort is too diminutive. The initial return on investment, or the net present value of the return, is less than the marginal effort. This is why breaking down a goal is so important, to increase the return per effort. It’s an uncomplicated but perceptual cost-benefit analysis.