To Örebro University

This paper discusses how incidences of unit taxes and ad valorem taxes are related to various market characteristics under imperfect competition. Incidence is higher the more competitive markets are. More specifically, it is higher the wider the firms' product ranges, the lower the degree of market concentration and the lower the degree of product differentiation, and higher in Bertrand markets compared to Cournot markets. Furthermore, the incidence is higher for unit taxes than for ad valorem taxes. The relative difference between unit and ad valorem tax incidence is larger the lower marginal costs and taxes are.

We present a model of the interaction between firms agreeing on a degree of collusion and a competition authority that simultaneously determines the allocation of resources to enforcement of anti-trust legislation. An increase in demand is associated with tougher enforcement and a lower degree of collusion. A stronger competitive pressure first decreases the degree of collusion and increases the level of enforcement, then increases both the degree of collusion and the level of enforcement, and eventually increases the degree of collusion and decreases the level of enforcement. Simulation results indicate that a move from the EU penalty regime to the tougher US standard with treble damages would mainly impact on the enforcement intensity and to a much lesser extent affect the degree of collusion.

This study develops a framework for the strategic interaction of firms that have to decide between adhering to and violating legislation. Depending on how deterring enforcement is various degrees of compliance with the law will arise in equilibrium. For an agency that targets a certain compliance rate more resources per firm should be allocated to industries with strong demand and high costs for adhering to legislation. Whenever some degree of non-compliance among competing firms can be expected, more inspection resources are needed in markets where products are highly differentiated and/or the number of firms is small.

This study focuses on the consequences of inducing compliance with environmental legislation through inspections in oligopolistic markets. Adherence to the law is associated with environmental gains, but also with losses in surpluses as firms incur abatement costs. By relating the net social benefit of deterring breaches of legislation to inspection costs, the impact of various market characteristics on the effectiveness of inspections can be assessed, thus providing guidance for environmental inspection agencies that have to prioritize among sectors given a fixed budget.

This paper discusses how marginal costs of public funds are related to various market characteristics under imperfect competition. Under a quite general tax scheme, these costs turn out to be lower the wider the firms' product ranges, the lower the degree of market concentration and the lower the degree of product differentiation. Moreover, marginal costs of taxation are lower in Bertrand markets compared to Cournot markets. In cases when marginal costs of public funds cannot easily be assessed we ask if pass-through rates can provide useful information for policy makers. The market characteristics that we analyze are shown to have opposite effects on pass-through and marginal costs of public funds. It is also demonstrated that the marginal cost of public funds is generally lower for ad valorem taxes than for unit taxes. The main results are based on a linear demand system, but a number of extensions confirm that our main results are reasonably robust.