This paper explores the role of mobile scientists in international networks and their relationship to the quality of published articles.  Data come from the GlobSci survey, conducted in the spring of 2011 by the three authors.  The methodology involved surveying corresponding authors of articles published in 2009 in four fields of science who were studying or working in one of the 16 countries. The four fields are biology, chemistry, earth and environmental sciences, and materials.  Collectively the core countries produce about 70 percent of all articles published in these fields.  For each specific discipline, we chose articles from a randomly picked selection of journals in each quartile of the Impact Factor distribution. Country of origin was determined by asking the corresponding author to report country of residence at age 18. 

Evidence on foreign-born patterns indicates a high heterogeneity across the 16 countries. The incidence of foreign born researchers, for example, ranges between 56% for Switzerland and 3% for Italy. The rate for the US is 38%, close to that of Sweden (37%) but lower than that of Canada (47%) and Australia (44%). The rate for Japan is very close to that of Italy (5%). 

The paper develops different econometric models that analyze for the 16 core countries the presence of significant differences between foreign-born researchers, native researchers who had an international training or working experience and subsequently returned, and native non-mobile researchers regarding their openness to establishing international collaborations and the quality of their research.  In particular we analyze the impact at the individual level of international mobility on the degree of openness to participation in international research networks and on the quality of internationally authored publications.  Openness to international research networks is measured by the number of countries with which the scientist has collaborated in the last two years. Research quality is measured using bibliometric indicators.

The structure of the dataset allows us to control for a number of individual characteristics, including age, gender, job position, type of affiliation, reasons for leaving the origin country, type of initial entry in the host country (for PhD training, post-doc, direct employment), scientific field characteristics (including multidisciplinarity, stage of development, number of competing research teams worldwide) and country of origin of the researchers. Preliminary results indicate that even after accounting for individual characteristics and scientific field specificities foreign-born scientists show on average a higher propensity to be involved in international collaborations. Moreover, we find that on average about 40% of foreign-born scientists declare having current scientific collaborations with researchers based in their origin countries. On average they also show a higher research output quality than native non-mobile although they tend to underperform natives with an international background that subsequently returned.