Excerpted from a pro-immigration blog post titled Economists’ Best Advice by Robin Hanson:

I am a proud resident of Fairfax County, in the U.S. state of Virginia. Today, I want to warn my fine fellow Fairfax folk: we interact too promiscuously with outsiders! For example, we are allowed to buy things made outside Fairfax, and leave the county to travel or work. Fairfax firms can even choose outsiders as investors, employees, and suppliers.

Such promiscuous interaction risks polluting our precious purity with uncontrolled contamination! Surely we choose to live in oh-so-fair Fairfax because we believe in Fairfax exceptionalism, in our exceptional mix of climate, culture, attitudes, laws, personalities, etc. Yet we allow any of us to risk corrupting this exceptionality via unrestricted mixing with outsiders. For example, we let outsiders move here who might vote for politicians who also don’t share our political values. And lets not forget that terrorists might slip in.

Much of this mixing surely also hurts Fairfax locals who compete with outsiders. Fairfax residents who drive to other counties to eat restaurant meals take business away from Fairfax restaurants. Fairfax firms that hire workers living in other counties take jobs away from Fairfax workers. Fairfax people who read books and blogs written by outsiders take readers away from Fairfax authors. Sure, sometimes we benefit from mixing with outsiders, and sometimes enough to compensate for losses to locals. But no one can prove that this is always the case, or even usually the case.

So, dear fellow Fairfax folks, we simply must be more careful! I’m not saying we should never interact with outsiders, but we must be more selective. There must be oversight – we can’t just let any of us decide for themselves how much they’ll pollute or harm the rest of us.