That wouldn't prove it harms workers. It would prove it benefits IBM. What benefits IBM may also benefit the rest of the US - for example, by lowering the cost

That wouldn't prove it harms workers. It would prove it benefits IBM. What benefits IBM may also benefit the rest of the US - for example, by lowering the cost of IBM's services. Labour economists have spent thousands of hours analysing data to understand the effects of migration. There are thirty years of papers. Some are quite good. It would be better if the public debate were more informed by this effort.