We update the analysis of Allan et al. (2015) and re-examine whether New Zealand households have become greener consumers using newly available data. We combine input-output data from 2006 and 2012 with detailed data on household consumption from the 2006 and 2012 Household Economic Surveys (HES) to calculate the greenhouse gas emissions embodied in household consumption. We confirm many of our previous findings that emissions increase less than proportionately with expenditure, and that there is significant variation in expenditure elasticities across consumption categories. We test for a change in household emissions over time and decompose this change into improvements in production efficiency and changes in households. We find that average household emissions fell by 11% between 2006 and 2012. We attribute 1.7 percentage points of this decrease to changes in households, with the remaining 9.3 percentage points from changes in emissions intensities. The majority of the change due to households is a result of changes in household behaviour rather than a change in household characteristics. Emissions from household energy fell markedly between 2006 and 2012, driven by a reduction in the emissions intensity of electricity and a decrease in household electricity consumption.
Motu Economic and Public Policy Research Trust and the authors 2016