Immigration in Order to Keep Things the Same

I had not looked at it this way, but Arcotherium over at Aporia points out that countries sometimes use immigration to avoid change and dynamism rather than create it. Industries don't have to modernise practices and equipment if they can import cheaper labor and keep doing it the old-fashioned way.  He mentions American agriculture, but there are worldwide examples and more industries in the US that evade change with immigration. He calls it Mortmain Migration: Immigration as an agent of stasis. 

But often the industry changes anyway, and we have a host of new immigrants who do not have other useful schools to adapt to American live, having grown up elsewhere.

 Rather than a rational system designed to favor the national interest or any other goal, Western immigration systems are accreted over time by blindly following the local incentive gradients that special interest lobbying creates. For such lobbying to matter, the special interests must have power and influence—which are the province of incumbents, not challengers. And it is declining incumbents (who have long since conquered their niche and ceased to innovate) that focus most organizational attention and resources on lobbying. Hence we should not be surprised to find that much Western immigration is designed to preserve declining incumbents.