Interactive price floor: the surplus and the blocked trades Government buys or stores the excess; sellers add free extras to attract buyers. S D Floor 5.0 Surplus (Qs − Qd) Deadweight loss (blocked trades) P* Q* Qd Qs Quantity Price ($) Floor at 5.0 → sellers offer 5, buyers take only 2 (Q* is 3.5). The trades between 2 and 3.5 were worth more to buyers than they cost sellers — that lost value is the deadweight loss; taxpayers buy or store the 3-unit surplus. Drag the brass floor line up or down, or press an arrow key.