I didn't have patience to read it.
However, I worked in the capital markets. There is very little foreign workers in it.
However, my job required me to interact with many portfolio managers, business leaders and I had access to these economic reports. Predictions on interest rates; emerging global powers, gross domestic product, effect of terrorism, iraq situation, geopolitical issues, etc.
Not one time was it ever mentioned that immigration was an issue that would impact the economy. It wouldn't even make top 10 list if they did create one.
The brightest and best are not bachelors graduates with one or two years of experience who come to USA on H-1b in essentially entry level positions and then gain experience while they are here. The brightest and best are proven commodities in their own countries. They are involved in significant scientific, business ventures. These people have so many avenues of coming here and getting the greencard. If these types of people can't get visas/greencards then you will see something change. If the CFO/CEO of major banks/financial institutions/software companies, etc. tell US business leaders that they don't want to come visit, do business in USA but because of immigration issues then you will see something change. However, that will never be the case.
There are a few things I've seen in my career/life that sort of shaped my opinion. One of them was when the commissioner of baseball banned Pete Rose for life from baseball because he bet on baseball games. For those non baseball fans; he had the record for most base hits in a lifetime. Bart Giamatti stated that "there is no one person bigger then the game of baseball". His ineference was we were here before and we will be here after. We are not dependent on one person.
Another common thing that happens is when you set up a business infrastructure. You do it in such a way to "plug and play". What this essentially means is that people are interchangeable. You cannot design it in such a way that it falls apart if one person leaves. All people are interchangeable. No matter how hard everyone wants to believe that things will fall apart if they leave or how a company will be screwed needs to keep that in perspective.
If CEO's of major public companies can retire, get fired and turn over every couple of years and companies don't miss a beat and in some cases even get stronger then what argument do you/we have that if they don't give you a greencard that this somehow will have such catastraphic results in short or long term?