TOKYO, Sept 10 (Reuters) - Japan must not make its public finances a target of experiment for lax financial management such as through “modern monetary theory”, Finance Minister Taro Aso said on Friday. Aso made the comment at a regular news conference, when asked about a proposal by Sanae Takaichi, a contender in the ruling party’s leadership race, for shelving a primary budget-balancing target until 2% inflation is met. (Reporting by Tetsushi Kajimoto; Editing by Muralikumar Anantharaman)