Template-Type: ReDIF-Paper 1.0 Series: Tinbergen Institute Discussion Papers Creation-Date: 2006-08-25 Number: 06-074/1 Author-Name: Marie Goppelsroeder Author-Email: goppels@hei.unige.ch Author-Workplace-Name: Graduate Institute of International Studies, Geneva, Switzerland Author-Name: Maarten Pieter Schinkel Author-Email: m.p.schinkel@uva.nl Author-Workplace-Name: Faculty of Economics and Business, Universiteit van Amsterdam Author-Name: Jan Tuinstra Author-Email: j.tuinstra@uva.nl Author-Workplace-Name: Faculty of Economics and Business, Universiteit van Amsterdam Title: Quantifying the Scope for Efficiency Defense in Merger Control: The Werden-Froeb-Index Abstract: This paper introduces the Werden-Froeb Index (WFI) to assist in evaluating merger-specific efficiencies in horizontal mergers. The index measures the weighted average reduction in marginal costs required to restore pre-merger equilibrium prices and quantities after the (full or partial) merger is consummated. The WFI is well defined, objective and robust, and it has relatively low information requirements. We propose to use the index as a natural complement to concentration measures such as the Hirschmann-Herfindahl Index in the assessment of horizontal mergers.

This discussion paper has resulted in a publication in The Journal of Industrial Economics, 56(4), 778-808. Classification-JEL: L100; L400; C430 Keywords: Merger control; efficiency defense; index; HHI File-Url: https://papers.tinbergen.nl/06074.pdf File-Format: application/pdf File-Size: 309816 bytes Handle: RePEc:tin:wpaper:20060074