The study explores how taxes on capital and labor income affect long-term economic growth. By using a model that considers human capital and labor market frictions, the researchers found that it is not always best to completely replace capital taxes with labor taxes. Instead, a partial switch is more optimal due to factors like job creation and worker participation. This finding holds true even when tax rates change over time. The study shows that factors like human capital formation and labor market dynamics play a crucial role in determining the best tax policies for economic growth.