But Canada’s hospitable attitude is not innate; it is, rather, the product of very hardheaded government policies. Ever since the mid-1960s, the majority of immigrants to the country (about 65 percent in 2015) have been admitted on purely economic grounds, having been evaluated under a nine-point rubric that ignores their race, religion and ethnicity and instead looks at their age, education, job skills, language ability and other attributes that define their potential contribution to the national work force.

No wonder this approach appeals to President Trump. He’s right to complain that America’s system makes no sense. The majority (about two-thirds in 2015) of immigrants to the United States are admitted under a program known as family reunification — in other words, their fate depends on whether they already have relatives in the country. Family reunification sounds nice on an emotional level (who doesn’t want to unite families?). But it’s a lousy basis for government policy, since it lets dumb luck — that is, whether some relative of yours had the good fortune to get here before you — shape the immigrant population.

The result? Well, contrary to popular myth (and Mr. Trump’s rhetoric), immigrants to the United States also outperform native-born Americans in some ways, including business creation and obedience to the law. But their achievements pale next to those of first-generation Canadians.

For example, about half of all Canadian immigrants arrive with a college degree, while the figure in the United States is just 27 percent. Immigrant children in Canadian schools read at the same level as the native born, while the gap is huge in the United States. Canadian immigrants are almost 20 percent more likely to own their own homes and 7 percent less likely to live in poverty than their American equivalents.

Mr. Trump has spoken about adopting a merit-based system before, and done nothing. And his speech in Iowa was short on specifics (he had more details on his idea for putting solar panels atop his border wall). But if he’s truly serious about reform, the president could do a lot worse than look north for answers. He wouldn’t even have to admit where he got them from. Canadians are a modest, unassuming lot, used to being overlooked and overshadowed. They won’t mind keeping his secret.