A considerable literature has focused on the determinants of total factor productivity (TFP), prompted by the empirical finding that TFP accounts for the bulk of long-term growth. This paper offers a deeper reason for such focus: the welfare of a representative consumer is summarized by current...

This paper shows that the welfare of a country's representative consumer can be measured using just two variables: current and future total factor productivity and the capital stock per capita. These variables suffice to calculate welfare changes within a country, as well as welfare differences...