Bus Merger, Diversion Ratios, and Depot Slots
Two bus operators propose a merger. On the 12 overlapping intercity routes, Operator A has 45% share, Operator B 25%, Operator C 15%, and fringe operators 15%. A and B are each other's closest substitutes: the diversion ratio from B to A is 0.4. The operators' average variable margin is 30%. Entry is difficult because depot slots at the central station are allocated by tender every seven years. The parties claim annual efficiencies of €6 million from depot consolidation and that B is a failing firm with debts of €20 million. The competition authority must decide whether to clear, clear with remedies, or prohibit. Consumer groups note that 30% of passengers are commuters with no car and that fares are regulated on only 4 of the 12 routes. The authority uses a SSNIP test and a GUPPI screen.
1. Define the relevant market and assess unilateral effects using the GUPPI and concentration data.
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Market definition should start with overlapping intercity bus routes where A and B are closest substitutes. A SSNIP would likely be profitable on routes where rail is not a close substitute and car ownership is low; the 30% carless commuters and regulated fares on only 4 routes suggest the relevant market may be narrower than all 12 routes. GUPPI = diversion ratio × margin = 0.4 × 30% = 12%. That is a meaningful upward pricing pressure screen, above typical safe harbours. HHI pre-merger = 45² + 25² + 15² + 15² = 3,100; post-merger = 70² + 15² + 15² = 5,350; delta = 2 × 45 × 25 = 2,250. The market is already concentrated and the merger creates a dominant firm. Unilateral effects are likely on overlap routes; coordinated effects are less clear, but the seven-year depot tender is a barrier.
2. Evaluate the failing-firm defence and the claimed efficiencies.
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The failing-firm defence requires imminent failure, no less anticompetitive alternative purchaser, and that the assets would exit. B's €20m debts suggest distress, but the authority must ask whether B would fail without the merger, whether another buyer could keep it as a competitor, and whether liquidation would transfer depot slots to A anyway. Efficiencies of €6m must be merger-specific, verifiable, and passed on to consumers. Depot consolidation may be merger-specific, but the parties must show it is not merely a financial transfer and that it outweighs the price effects. A GUPPI of 12% implies a significant incentive to raise fares; €6m may be small relative to consumer harm on 12 routes. The authority should discount claimed efficiencies that could be achieved by competition or by a less restrictive remedy.
3. Choose between clearance, remedies, and prohibition, and justify the remedy design.
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Prohibit the merger as notified, or clear only with divestiture of overlapping routes and sufficient depot slots to a viable entrant. A behavioural fare cap is weak because regulated fares cover only 4 routes and the authority would need costly monitoring. Structural divestiture addresses the unilateral incentive directly; the depot slots are the key input, so divesting routes without slots is insufficient. If the failing-firm case is strong, a conditional clearance with a crown-jewel divestiture and a trustee may be appropriate. The authority should compare the counterfactual (B's exit) with the merger, not with the status quo, and should require that any remedy be proportionate and verifiable.