With globalization, the trade of goods has considerably increased. But the substitution to international trade, international migration has also increased. While the migration of low-skilled workers draws headlines, the most "globalized" are the high-skilled ones. In particular, those holding doctorates are very mobile and in particular they move frequently.
Laudeline Auriol has analyzed for the OECD the flow of doctorates across its members countries. For examples, across European countries, 15 to 30% of all doctorate holders has moved across a border over the last 10 years. This is a remarkable transformation for Europe, where language and cultural barriers were much much higher a few decades ago.
This high mobility reflects the particular labor market for doctorates. Positions and candidates are very specialized, thus often need to move far to fond a match. This is compounded by the large increase in new doctorates across the OECD: from 140'000 in 1998 to 200'000 in 2006. But this growth has been very uneven, low in Germany, France and the US, very high for some of the poorer OECD countries, and for women. Currently, the US has the most doctorates (340'000) with Germany not far behind, which explains why a professorship there requires a second doctorate (habilitation).
Unemployment rates are low, 2-3%, but it usually takes several years after graduation until a doctorate finds a stable job, and this after graduating at a much higher age than other workers. While this sort of indicates a healthy labor market, it hides considerable heterogeneity. Women and doctorates in humanities face much higher unemployment rates. The latter are much less mobile because their research (and teaching) topic is much more closely related to the local cultural context, and can thus not take advantage of international opportunities like, say. natural scientists. It is then not surprising that in some countries a fifth hold jobs that are not related to their doctorates. There is also considerable uncertainty about job security. For example, post-docs (which include temporary visiting positions) now outnumber full-time faculty at US academic institutions.
Coming back to international mobility, it is remarkable how in most counties over a fifth of doctorate holders are foreign born, over half in Canada. Half of the foreign born doctorates in the US are from Asia, and two-thirds of the graduate students as well. And in the countries that have lower proportions of foreign born considerable share has stayed abroad recently. A truly international workforce.