The change in the capital stock per worker (known as capital deepening) is equal to per worker gross investment minus depreciation: ∆k = i - δk.
A company's accounting team might calculate the stated value of all capital shares issued for financial reporting purposes. To calculate the value of capital stock, use the following formula:Value of capital stock = (Par value per share) x (Number of shares issued)Related: What Is Stockholder's Equity?
The Solow growth model focuses on long-run economic growth. A key component of economic growth is saving and investment. An increase in saving and investment raises the capital stock and thus raises the full-employment national income and product.
The overall change in the capital stock is equal to new investment minus depreciation: change in capital stock = new investment − depreciation rate × capital stock.
Changes in capital stock can affect employment levels, as more capital often means more jobs are created to operate and maintain new equipment. Increased capital stock can lead to lower production costs per unit, which can enhance competitiveness in both domestic and international markets.
To be more specific, the steady state level of capital solves the following equation: k = k(1 − δ) + sAf(k). At the steady state, the amount of capital lost by depreciation is exactly offset by saving.
For the change in the capital stock per worker, as opposed to the rate of change, multiply each side by k, or K/L, as convenient: ∆k = (I/K - δK/K)K/L – nk = I/L - δK/L – nk, this simplifies to: ∆k = i – (δ + n)k.
Steady state represents the equilibrium of the economy in the long term. Equilibrium occurs exactly when the investment equals the break-even investment. As a result, capital stock does not change.
The key assumption of the Solow–Swan growth model is that capital is subject to diminishing returns in a closed economy. Given a fixed stock of labor, the impact on output of the last unit of capital accumulated will always be less than the one before.