Using a Rebound Matrix to Estimate Consumption Changes from Saving and its Environmental Impact in Japan

We investigate the extent to which Japanese people can change their consumption and the corresponding environmental impact. We propose a new analytical framework with a rebound matrix that captures the monetary flow from potential savings to their respending (referred to as rebound). A questionnaire is used to derive the matrix. On average, respondents spent 3.4 million Yen annually, resulting in 12.4 tons of carbon dioxide (CO₂) emissions in their daily lives. The survey results suggest that acceptable spending reductions would correspond to a CO₂ emissions reduction of nearly 6%. However, the CO₂ emissions would increase by nearly the same amount when the respondents respend their savable money (rebound CO₂ emissions). The annual CO₂ emissions and the annually reducible CO₂ emissions both increase with the increase in annual expenditure. Consequently, the net CO₂ emissions also increase with the increase in annual expenditure. The rebound spending is approximated using the rebound matrix. Finally, it is suggested that the net CO₂ emissions can be reduced through lifestyle changes whereby spending on energy items is reduced and the resulting savings are spent on telecommunication, clothes, shoes, education, and housing.