Principles of Macroeconomics / Unit 2 MAC 0129 worked example, 60 to 90 seconds
Who Gains and Who Loses from a Control
The idea
A binding control has three effects, and keeping them apart is the whole skill. First, a transfer: a ceiling moves surplus from sellers to the buyers who still get the good, and a floor moves surplus from buyers to the sellers who still sell. Second, an exclusion: the quantity traded falls, so some buyers and some sellers who would have traded do not, and they lose entirely. Third, a deadweight loss: the surplus those blocked trades would have created is destroyed and goes to no one.
In practice
Worked example: a binding ceiling on a good. Buyers who obtain it at the capped price gain. Sellers who still sell receive less, so they lose. Buyers who wanted the good and cannot find it gain nothing at all. Sellers who would have supplied the units no longer produced also lose. Total surplus falls, so the gains to the first group are smaller than the losses to everyone else.
Where people slip
The trap is to treat a control as costless because someone visibly gains. Ask each time who is excluded, since those people are absent from the market and easy to overlook, and they are usually the ones the policy was written for.
Your place on the trail
Every lesson rests on earlier ones and opens later ones. Tap any to jump.
Unlocks
- Nothing yet depends on this.
Something wrong in this lesson? Flag it · Sources for Principles of Macroeconomics