Utilitarianism comes tied in my head with wealth distribution, but perhaps you're right. I see myself looking at this from a US vs THEM perspective, where my role and responsibility would be towards only the nation I represent, and not to anyone else.

In business, while it might be cheaper for me and my business partner to share a lawyer to come to a legal agreement on our partnership details, we both will instead get our own lawyers that will best represent the interest of the individual and not the group. On a world stage, what might be best for the world isn't necessary what is best for the nation I represent. I

In the case of a refugee crisis, I could perhaps see the world as a whole feeling some responsibly for the refugee crisis, but that assumes the world as a whole cared for its components; if it did, it would ensure the refugees were protected. To achieve this, it would perhaps require international unity and shared sense of responsibility. The world has fairly week unity and leadership though; it instead remains largely a set of competitive nation states. The need for borders or wars may not even exist in a world that was indeed unified.

If humans are able to reach other star systems as colonists, I'd believe the thought of such a unified human race would seem implausible. It may be due to that that we are all still trapped sharing the same small globe that we feel unity is desirable or even possible. The world may need to get quite a bit smaller before that realistically can happen though, and until then, US vs THEM seems to prevail in my head. Even states battle between themselves still, despite sharing a common flag.

As a nation state, perhaps allowing other nation states to sponsor refugees to afford the cost of entry into my nation would work. The 'moral' responsibility would then be shared amongst all world actors. The concern for me then would be to correctly cost out the long term and short term burden of it all. Would it be immoral to try to turn a profit if possible?

In regards to your 'in built' or 'static' characteristics comment, I'd probably say the statistics of 1 in N I presented would incorporate those dynamic aspects. Lets assume this could be achieved by means of predictive models or observations of final outcomes.

Regarding financial influence, let's assume then that the resource availability is finite and the crime statistics presented considers maximum allowable investment for the two pollution sizes. Larger populations might not have as much investment per individual, resulting perhaps partially in the increased violence rates.

I've generally tried to narrow the conditions and variables to focus on the altruistic and ethical branch of making such a decision. If ethics is not a primary factor in making such a decision, that's interesting, although I'd still be curious to take the discussion to an artificial situation where it was.

And a population influx can bring about advantages too: a broader tax base for a government, more circulating money in an economy, skills and jobs, differing perspectives etc. And of course these are just some parameters that need to be balanced out with others, which can be as much of an economic matter as it can be an ethical or political one.

Seems like a valid argument. I suppose this triggers a deeper aspect of my confusion here, as there are often scenarios where there are no combined economic advantage from allowing in refugees, yet altruism stands strong still in open debates. If there was a benefit of allowing in mass populations, I'd imagine the nation would have open borders already, or at least be at its maximum beneficial level of immigrant influx.

It may be possible to further filter the refugees to include those only capable of providing an economic benefit: skill, job, wealth. I'd imagine that this would only dwindle the number of refugees allowed in to a much smaller number though, perhaps to levels of existing immigration levels. Diversity of immigrants under such a scenario may also be impacted, where non-refugee immigrants end up being rejected as a result.