As a research fellow at the Sasakawa Peace Foundation USA from 2014 until March 2020, I developed a polling aggregator to track the Abe cabinet’s approval and disapproval ratings. I wanted to continue aggregating Japan’s opinion polls, and so I am reviving what had formerly been called Japan Political Pulse here, at my own site.
I provided an explanation of my methodology here. My aggregation is not particularly sophisticated. Current polls are averaged together, weighted by sample size. To adjust for the “staleness” of a poll, the sample size is adjusted according to an exponential decay formula. After ten days in the sample, a poll is removed, unless no new polls have appeared, in which case the sample size continues to be adjusted downwards until new polls appear.
I include the following polls in my sample: Kyodo News; Jiji Press; Yomiuri Shimbun; Asahi Shimbun; Nikkei Shimbun; Mainichi Shimbun; NHK; Asahi News Network. Like all polling aggregators, my hope is that by consolidating these polls, I am able to limit whatever biases are present in the individual polls and find a “truer” picture of the government’s support on any given day.
While I have a spreadsheet dating back to 2015, I am only displaying data since the last general election, 22 October 2017, in the interest of space and legibility.