Question: who defines economics as the science of wealth
[{'answer': 'Alfred Marshall', 'provenance': [{'wikipedia_id': '2051863', 'title': 'Welfare definition of economics', 'start_paragraph_id': 1, 'start_character': 55, 'end_paragraph_id': 1, 'end_character': 70, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '2051863', 'title': 'Welfare definition of economics', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 666, 'bleu_score': 0.9808590314834971, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 551484298672787607}, 'section': 'Section::::Abstract.'}]}]