Write consumption per worker as a function of the capital stock in steady-state. An increase in saving and investment raises the capital stock and thus raises the full-employment national income and product.From this expression, we can see that the capital stock in the steady state is increasing in the saving rate s and decreasing in the depreciation rate δ. How does the capital stock per worker evolve over time? At each point in time there is investment and thus capital stock per worker goes up. Solow's model is an exercise in math without any economics in it. The labor-capital ratio is not a random or arbitrary number. The Solow Growth Model is an exogenous model of economic growth that analyzes changes in the level of output in an economy over time. A Power Law for Energy Consumption of Economies.