Frequent readers will know that I am a strong supporter of open immigration. I don't disagree with McQ at Q&O when he writes "Open Borders or Welfare State: Pick One," but I don't think that this is the logic of most folks who are anti-immigration. It may be their public stance, but if more folks really thought this way, there would be serious discussion of tiered citizenship or guest worker models similar to what I have proposed on several occasions.
However, I am tempted to become a close-the-border proponent if the left continue to use numbers skewed by immigration to justify expansions of taxation and the welfare state. Whether they are illegal or not, whether they should be allowed to stay or not, the fact is that tens of millions of generally poor and unskilled immigrants have entered this country over the last several decades. These folks dominate the lower quintile of wage earners in this country, and skew all of our traditional economic indicators downwards. Median wages appear to be stagnating? Of course the metric looks this way -- as wages have risen, 10 million new folks have been inserted at the bottom. If you really want to know what the current median wage is on an apples to apples basis back to 1970, take the current reported median wage and count up about 10 million spots, and that should be the number -- and it will be much higher.
Income distribution numbers are the same way. I showed in a previous post how these numbers are deceptive, when we compare them to Europe, because though European poor have a higher percentage of the median wage in their country, it is a higher percentage of a lower number. When you correct for that effect, the US poor look pretty equal. But immigration exaggerates this effect even more. Instead of having income distribution numbers comparing, say, a lawyer and a blue collar worker, they are now comparing a lawyer and a non-English-speaking recent unskilled immigrant. Of course the disparity looks worse!
The folks using these numbers have to be smart enough to understand this issue, so it can only be hugely disingenuous that they simultaneously promote immigration (which I support) while at the same time using immigrant-skewed numbers to say that the average US worker is somehow worse off. If they keep this tactic up, even I may be tempted to close the borders.