Although material transfer agreements may be useful to exchange research materials between laboratories, academics and policymakers have suggested that the trend towards their standardisation might impede the progress of science by constraining one type of research collaboration: the...

This paper examines the determinants of researcher contribution-spans. The contribution-span is the number of years spanning a researcher's first and last known publications in a field. It serves as a unique measure of researchers' persistence. Based on co-authorship data, several sociometric...