economic theory prescribes that the advertising volume can be optimally reduced by levying a tax on ads. However, making use of … recent advances in the theory of Industrial Organization and two-sided markets we show that taxing ads may be …

If an additional competitor reduces output per firm in a homogenous Cournot-oligopoly, market entry will be excessive … the excessive entry prediction. Tax evasion raises the number of firms in market equilibrium and can alter their welfare …-maximizing number. In consequence, evasion can aggravate or mitigate excessive entry. Which of these outcomes prevails is determined by …

evaluation is also justified in a Cournot-oligopoly with free but costly entry. If input markets are competitive and output per … firm declines with the number of firms (business stealing), there is excessive entry into such oligopoly. If trade unions … raise wages above the competitive level, output and profits per firm decline, which could deter entry and thus improve …

CSR as an entry deterrent. Both results indicate that CSR may increase market concentration. Third, we consider …

. That includes mergers that are known to be unprofitable in the corresponding static equilibrium framework. …