There is a theory by Koji HIRATA and others that Kanpyo no chi was a transition and preparatory period for the dynasty state system led by SUGAWARA no Michizane and Engi no chi was intended to transit to the national system ruled by imperial families by Tokihira who took over the idea of Michizane, but the details were unknown because the political records of Michizane were destroyed by Tokihira.
なお、寛平の治は菅原道真の主導による王朝国家体制への転換準備期であり、延喜の治は道真の着想を引き継いだ時平による王朝国家体制への移行を意図したものであったが、時平により道真の政治の記録が抹殺されたため詳細が不明となっていたにすぎないとする平田耿二等の説がある。