I’m looking for any kinds of statistics indicating how many people living in third world countries work for western multi-national coroprations.
You’ve got to define third-world a little better these days, I think. India comes to mind as being a place that would radically change the numbers to this answer. Then China.
You may be able to get statistics from consulting firms that conduct census surveys with large, multi-national employers to gather this kind of employment data. Some consulting firms that come to mind are WatsonWyatt, Organizational Resource Counselors and Mercer. However, you may have to pay for the data and survey results can be expensive.
You could also try searching the internet for statistics on “local nationals” or “host country nationals.” These are universal employment terms for people who are hired for jobs in their own countries.
Throwing a monkey wrench into any stats is the fact that a significant part of the Third world employment is indirect. For example, Nike does not employ foreign workers. Nike contracts with companies overseas to supply shoes, and those companies are the ones that actually do the employment.