A number of studies are increasingly trying to assess these aspects. Given that non-tariff barriers or measures are less transparent than tariff measures, it is much more difficult to quantify their economic effects.
I would like to make two brief comments in response to your question.
With regard to tariff measures, under the rules of the World Trade Organization, all countries have a limit on the tariffs they can apply. They are obliged, under their schedule of commitments, not to impose tariffs above the negotiated threshold. Therefore, a country like Canada does not really have the flexibility to raise its tariffs unilaterally, except in very specific cases, but they are very limited. The same is true for other countries. They can't raise their tariffs very easily.
Second, if a country has a tariff protection measure in the form of a tariff, that is very clear. However, non-tariff barriers are more difficult to quantify. Not all measures are on equal footing with regard to their effects on trade. As I mentioned in my opening remarks, several of these measures are legitimate, but our American colleagues may differ on the legitimacy of a Canadian measure. If there is disagreement, the matter will be referred to an arbitration tribunal of the World Trade Organization.
Increasingly, measures that restrict trade are not tariff measures because, with successive rounds of negotiations, tariffs have gone down. Now, more and more, the barriers are non-tariff. We talked this morning about the tools we have at our fingertips to defend our interests. Bilateral discussions or regulatory cooperation are the tools we have to try to overcome these obstacles.