We analyse the key determinants of umbrella effects, which arise when the price increase or quantity reduction of a cartel diverts demand to substitute products. Umbrella effects arise irrespective of whether non cartelists act as price takers (“competitive fringe”) or respond strategically...

The paper revisits the conventional wisdom according to which vertical restrictions on retail prices help upstream firms to collude. We analyse the scope for collusion with and without resale price maintenance (RPM) when retailers observe local shocks on demand or retail costs. In the absence of...

In this paper, two pairs of complementors have to decide whether to merge and eventually bundle their products. Depending on the degree of competitive pressure in the market, either both pairs decide to merge (with or without bundling), or only one pair merges and bundles, while rivals remain...

The most important issues in auction design are the traditional concerns of competition policy-preventing collusive, predatory, and entry deterring behaviour. Ascending and uniform-price auctions are particularly vulnerable to these problems (we discuss radiospectrum and football TV-rights...

In this paper, two pairs of complementors have to decide whether to merge and eventually bundle their products. Depending on the degree of competitive pressure in the market, either both pairs decide to merge (with or without bundling), or only one pair merges and bundles, while rivals remain...