The duty examples are arithmetic, not measured retail savings. We have no total GDP loss for current Canadian import barriers.
Start with a real item
The 2026 schedule puts cotton T-shirts in item 6109.10.00. Its standard trade rate is 18%. Some listed trade rates are lower or zero. The same shirt can face a different bill based on its origin and the proof supplied.
At that 18% rate, a $10 customs value gives $1.80 in duty. That does not mean a store price falls by $1.80 if the duty ends. Sellers and buyers may share the gain.
Follow every layer
For each item, record the product code, origin, date and trade rate. Then check extra duties, quota permits, exclusions and any relief from duty. Keep freight, broker fees and sales tax on separate lines.
Extra duties for dumping or foreign aid need their own file. Dumping is a legal test about export prices, not just a word for cheap goods. Show the finding, its scope, its expiry and the cost to firms that use the goods.
A tax bill is not a GDP loss
GDP is the value of goods and services a country produces. Duty paid to the state is tax revenue. It is not all lost output. The real cost can include purchases that never happen, costlier parts and less pressure to improve.
Ending a tariff cuts that revenue. Count the public budget effect, gains to buyers, changes in output and help for workers apart. Do not add them as if they were the same thing. Our aim is to end protection, with an honest bill.