When you're applying for a legal career afterward, they'll often look at your law school and your undergraduate major. A lawyer with an economics background is certainly going to stand out from the crowd when surrounded with 100 applicants who majored in Poli Sci. Ditto engineering. I was reading a study based in the States (couldn't find data on Canada) that showed that the average income for a law school graduates who majored in Economics or Engineering in undergrad was almost 20k higher than law graduates who majored in Poli Sci in the first 4 or 5 years after school (after 7 or 8 years they tended to converge).