{'fraction_non_alphanumeric': 0.01918158567774936, 'fraction_numerical': 0.0, 'mean_word_length': 4.673913043478261, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Oligopoly and Customs Unions

We analyze a model of international oligopoly when customs unions are possible. We show that importer-exporter customs unions are pro-competitive in the sense that internally they will tend to have industries produce at their competitive output level, but will tend to exclude imports from non-member countries. Exporter customs unions are anti-competitive and will produce the monopoly output. We apply core theory to determine which unions would form. With one firm in each country the importer will form a union with the low cost exporter. With identical costs, but variable numbers of firms, when the number of firms is small an importer-exporter customs union forms. A union of the exporters will form if there are four or more firms in the world.