Question: a parallel shift in the budget line is caused by changes in the relative prices of the two goods
[{'answer': 'income effect', 'provenance': [{'wikipedia_id': '469727', 'title': 'Income–consumption curve', 'start_paragraph_id': 2, 'start_character': 4, 'end_paragraph_id': 2, 'end_character': 17, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '469727', 'title': 'Income–consumption curve', 'start_paragraph_id': 2, 'start_character': 0, 'end_paragraph_id': 2, 'end_character': 634, 'bleu_score': 0.9825310706027971, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 2581346166757606273}, 'section': 'Section::::Abstract.'}]}]