A tale of two Canadas: Where you grew up affects your income in adulthood

You also have to remember that social mobility can be skewed by wealth distribution. Let's say a person goes from earning $75K to $100K in Canada. That might mean you moved from the 3rd quintile to the 5th quintile. But the same person moving from $75K to $125K in the US might only move from the 3rd quintile to the 4th, even though the US person overall improved their situation more.

I'm only partially kidding; all the best people in my class making the most money moved to the US immediately upon graduation.

For those born in the US, there's less movement and that's exactly what would be expected in a system that has been relatively meritocratic for multiple generations. Regardless of whether of the previous generation excelled due to cultural or hereditary reasons, their children will likely inherit both. Children also inherit money, which is a factor. However, if money were the primary factor, poor immigrant families would tend to remain poor and they don't.

The times when there's a great deal of mobility between generations of native populations is when there's a change in structural obstacles (or benefits). This can be seen especially clearly in Jewish populations in the US when various discriminatory regulations were removed early last century or with (ethnically) Asian Americans later in the century. In both cases, many families made rapid gains in relative income and wealth. In the subsequent generation, children of the winners generally kept winning and metrics of "social mobility" displayed a decline, even though society had become objectively fairer than it had been two generations before.

This isn't to say society is "fair" now, only that simple inter-generational economic mobility comparisons poorly answer the question of where a conscientious person with no money would have the best chance of success.

The income quintile boundaries are set nationally, but the movements are divided locally, there is no such requirement for balancing in a single area. In theory, a single location could have 100% of people moving into the national top quintile.

edit: I'm referring to the chart called Rags-to-riches income mobility

I would like to see what it is like for a small sliding scale. Give me the same data with the ability to slide it over a 10 year or 10 month period. Do the smaller population areas flip back and forth between "mobile" and "immobile"?

Even a glance at the map disproves your point. BC outside of Vancouver and Victoria is relatively socially conservative, but it's a sea of red due to the lack of labour demand in those rural areas.

Sure, if you want to completely ignore the effect of two of biggest economic developments of the past quarter century.

Namely, the oil boom in (conservative) Alberta and the fisheries collapse in the (liberal) Maritimes.