...there is a second main factor that spawns new economic fallacies every day. This is the persistent tendency of men to see only the immediate effects of a given policy, or its effects only on a special group, and to neglect to inquire what the long-run effects of that policy will be not only on that special group but on all groups. It is the policy of overlooking secondary consequences.
In this lies almost the whole difference between good economics and bad. The bad economist sees only what immediately strikes the eye; the good economist also looks beyond...
–Economics in One Lesson: The Shortest and Surest Way to Understand Basic Economics by Henry Hazlitt