And jinka happened especially centering on Togoku during the period of the subjection of indigenous inhabitants in eastern Japan, and for Tei MORITA, military and economical burdens became heavy in Togoku because of the subjection of indigenous inhabitants in eastern Japan and the political dissatisfaction made such incidents happen as one factor, and kokushi became zuryo (provincial governor) and thus the relation between kokushi and gunji changed, which is assumed to have been the cause of decrease of jinka incidents.
なお、神火の発生は蝦夷征討期の東国に特に集中しており、森田悌は蝦夷征討によって東国において軍事的・経済的負担が強まり、政治的不満がこうした事件を引き起こす一因としてあったこと、国司の受領化によって国司と郡司の関係が変化したことが、神火事件減少の原因と推定している。