Price is set at the margin. If America is physically incapable of supplying 100% of its own lumber needs, then that Canadian lumber is the marginal good, and

Price is set at the margin. If America is physically incapable of supplying 100% of its own lumber needs, then that Canadian lumber is the marginal good, and the price of 100% of lumber will go up, not just the Canadian stuff. Two things that will prevent that: - inertia - it's likely that Canadian lumber before the tariffs wasn't the marginal good, wasn't the highest cost supplier. If Canadian suppliers were making 10% more profit than the previously marginal supplier, the price will go up 40% instead of 50%, Canadian suppliers absorbing that 10%.