Of course, however, the question here is, at what point do slaveholders rise up in violent opposition to abolition laws?
Is it based on the % of profits their slaves might bring?
No, historically that's irrelevant.
Historically, what matters is how large is the slaveholder and slave community relative to the total population?
Historically, where slaves accounted for more than 15% but less than 90% of a population, then slaveholders rose up in violent opposition to abolition.
This was notably true in US Southern slave-states, where states with 15% or fewer slave populations remained loyal Union states, while those with more than 15% joined the Confederate war against the United States.
In Brazil, slavery was just as profitable as in the United States, however, by 1888 the numbers of slaves had fallen from around 25% in 1830 to only 5% in 1888, and the result was peaceful abolition.
So, peaceful abolition did not depend on slavery's profitability, but it did depend on the overall numbers of slaves in the total population -- 15% seems to be the dividing line between peace and war.
Directly proportional to profitability.
As I said before, and common sense will tell you this is correct, if slaves had been profitable in the North, they would have never given them up.
It is in the nature of the vast majority of people to always put their own self interests above those of others.
As I said, the North could buy their position of "moral superiority" on the cheap. Had it cost them dearly, they would have balked.
Are you speaking of per capita or total contributions to the national economies of the two countries?