How many cartels are there? The answer is important in assessing the efficiency of competition policy. We present a Hidden Markov Model that answers the question, taking into account that often we do not know whether a cartel exists in an industry or not. Our model identifies key policy...

How many cartels are there? The answer is important in assessing the need for competition policy. We present a Hidden Markov Model that answers the question, taking into account that often we do not know whether a cartel exists in an industry or not. We take the model to data from a period of...

How many cartels are there? The answer is important in assessing the efficiency of competition policy. We present a Hidden Markov Model that answers the question, taking into account that often we do not know whether a cartel exists in an industry or not. Our model identifies key policy...

We study cartel contracts using data on 18 contract clauses of 109 legal Finnish manufacturing cartels. One third of the clauses relate to raising profits; the others deal with instability through incentive compatibility, cartel organization, or external threats. Cartels use three main...

We use grocery data from Norway and COVID-19 border closings to gauge the effect of cross-border shopping on commodity tax revenue. Detailed store-category level data identify differential treatment effects that depend on distance to Swedish stores. Economically significant effects extend to up...

First, we analyze how regular days off from competition and a time-dependent price pattern affect firm performance. Second, we examine the effects on firms' profitability from consumers' changing search- and timing behavior. We use microdata from gasoline retailing in Norway. Since 2004, firms...