Score contribution per author:
α: calibrated so average coauthorship-adjusted count equals average raw count
Social contacts help to find jobs, but not necessarily in the occupations where workers are most productive. Hence social contacts can generate mismatch between workers' occupational choices and their productive advantage. Accordingly, social networks can lead to low labour force quality, low returns to firms' investment and depressed aggregate productivity. We analyse surveys from both the US and Europe including information on job finding through contacts. Consistent with our predictions, contacts reduce unemployment duration by 1–3 months on average, but they are associated with wage discounts of at least 2.5%. We also find some evidence of negative externalities on aggregate productivity.