Marginal costs. Keep in mind that marginal means on the edge of something, so the cost of producing one more unit would be on the edge. Hope this explanation helps.
Answer:
segregation and prejudice
Explanation:
75 percent disease 25 percent indians
Well one push factor would be they wanted to escape religious and political prosecution. Another is the Potato Famine. This was when their potatoes were contaminated and many died from starvation and disease.
I hope this helps somehow ;)