In gathering demographic information, Yoshimune TOKUGAWA noticed a sharp population decline of 9,263 persons between September 1723 to April 1724 and a population surge of 10,394 persons between April and June 1725; After ordering an investigation into the seasonal fluctuations in population, it was discovered that frequent fires in winter prompted women and children to take shelter in neighboring towns and parental residences, and reconstruction work and the construction of dozo (earthen storehouse) from spring brought in an influx of workers.
徳川吉宗は享保八年（1723年）九月から享保九年（1724年）四月の間の9263人の急激な人口減少、享保十年（1725年）四月から六月の間の1万0394人の急激な人口増加に気付き、季節的な人口変動の理由を調べさせた結果、冬の火災の多さから特に子女は近隣実家等へ疎開する、春以降火災からの復興再建や土蔵の建築が増えて労働転入者も増える、などといった実態が判明している。