Maggie's Farm

From Bastiat's What is Seen and What is Not Seen. It's basically The Law of Unintended Consequences:

There is only one difference between a bad economist and a good one: the bad economist confines himself to the visible effect; the good economist takes into account both the effect that can be seen and those effects that must be foreseen.

1.3

Yet this difference is tremendous; for it almost always happens that
when the immediate consequence is favorable, the later consequences are
disastrous, and vice versa. Whence it follows that the bad economist
pursues a small present good that will be followed by a great evil to
come, while the good economist pursues a great good to come, at the risk
of a small present evil.

Topic comes up via Williamson's What Is Seen and Unseen: Obamacare Edition, which begins:

The Democrats’ strategy on Obamacare is cynical, and kind of
embarrassing: “Meet Jimmy, who will get something from the health-care
bill. How dare you take it away?” But there is the seen and there is the unseen. The beneficiaries of Obamacare are easy to find. They are what is seen. What is unseen?