I don’t think whether the group’s average output increases or decreases is the right metric. What’s important is whether the newly enlarged group’s output is higher than what the group and its new members’ total output would be if the groups weren’t merged—do the immigrants become more productive by immigrating, and do they make the native population more or less productive?
I don’t think whether the group’s average output increases or decreases is the right metric. What’s important is whether the newly enlarged group’s output is higher than what the group and its new members’ total output would be if the groups weren’t merged—do the immigrants become more productive by immigrating, and do they make the native population more or less productive?