Ask what follows from the consequences, not just from the action.
Its practical form is asking what happens next and then what happens after that. Price controls, rent caps and pesticide programmes all look sound at the first order and fail at the second.
In practice
- A rent cap holds rents for sitting tenants and thins the supply the next cohort will need, which shows up only in the second year.
- A firm that cuts its training budget improves this year's margin and raises next year's recruitment cost by more.