In the first half of the nineteenth century, the famous French economic journalist Frédéric Bastiat often distinguished in his writing between the “seen” and the “unseen.” The seen were the obvious visible consequences of an action or policy. The unseen were the less obvious, and often unintended, consequences. In his famous essay “What Is Seen and What Is Not Seen,” Bastiat wrote:
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.
Bastiat applied his analysis to a wide range of issues, including trade barriers, taxes, and government spending.