  The ability to activate and manage effective collaborations is becoming an
increasingly important criteria in policies on academic career advancement. The
rise of such policies leads to development of indicators that permit
measurement of the propensity to collaborate for academics of different ranks,
and to examine the role of several variables in collaboration, first among
these being the researchers' disciplines. In this work we apply an innovative
bibliometric approach based on individual propensity for collaboration to
measure the differences in propensity across academic ranks, by discipline and
for choice of collaboration forms - intramural, extramural domestic and
international. The analysis is based on the scientific production of Italian
academics for the period 2006 to 2010, totaling over 200,000 publications
indexed in Web of Science. It shows that assistant professors register a
propensity for intramural collaboration that is clearly greater than for
professors of higher ranks. Vice versa, the higher ranks, but not quite so
clearly, register greater propensity to collaborate at the international level.
