Tapered US carbon emissions during good times: what's old, what's new?

In light of a slow buildup in CO₂ emissions since the recovery, this paper revisits the relationship between CO₂ emissions and the US economy using a nonlinear autoregressive distributed lag model, in which the determinants are identified through an expanded real business cycle model. We find convincing evidence that CO₂ emissions decline more rapidly during recessions than increase during expansions over the long run. Of all determinants considered, long-run asymmetry is fostered once vehicle miles traveled is controlled. This calls for a greater attention to public transportation development and vehicle miles traveled tax for slowing down stock buildup of CO₂ emissions during good times.