Question: the united states is an example of what type of economy
[{'answer': 'highly developed mixed economy', 'provenance': [{'wikipedia_id': '32022', 'title': 'Economy of the United States', 'start_paragraph_id': 1, 'start_character': 38, 'end_paragraph_id': 1, 'end_character': 68, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '32022', 'title': 'Economy of the United States', 'start_paragraph_id': 1, 'start_character': 133, 'end_paragraph_id': 1, 'end_character': 1047, 'bleu_score': 0.7762960743078481, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 7864538196970782856}, 'section': 'Section::::Abstract.'}]}]