[CLAIM]
State-level carbon emissions and average working hours have a strong, positive relationship, which holds across a variety of model estimation techniques and net of various political, economic, and demographic drivers of emissions. Specifically, they find that, over time, a 1 percent increase in average working hours per worker is associated with a 0.668 percent increase in emissions, holding all else constant

[HYPOTHESIS]
Average working hours per worker in a state will be positively associated with carbon emissions.