We investigate whether and how social ties affect performance in teams by implementing a field experiment in which a sample of undergraduate students are randomly assigned to either teams composed by friends or teams composed by individuals not linked by friendship relationships. Students...

Criticisms vis-à-vis cluster policy are numerous, often confusing and really unhelpful; while some authors systematically question the merits, others on the contrary play a genuine role of counsel in his favour. This paper attempts to refocus the debate and analyses the economic issues, impacts...