Before revision:  In particular, we measure the time-varying degree of market efficiency using new datasets of the stock price index estimated by Hirayama (2017a,b, 2018, 2019a  ).
After revision:  In particular, we measure the time-varying degree of market efficiency using new datasets of the stock price index estimated by Hirayama (2017a,b, 2018, 2019a , 2020 ).