Clustered bids and a missing mass of nearly tied bids have both been proposed as markers of collusion. We present causal empirical evidence from an actual pro- curement cartel that bidding involves both…

We study how the threat of entry affects service quantity and quality of general practitioners (GPs). We leverage Germany’s needs-based primary care planning system, in which the likelihood of new GPs reduces by…

Governments increasingly use nudges to improve tax collection. We synthesise the growing literature on nudging experiments using meta-analytical methods. We find that, relative to the baseline where about a…