Even in this seemingly simple case, the distinction may not be clear. If fertilizer use helps maintain and build soil fertility in the long run, it may also be considered an investment. Similarly, in public expenditures, a distinction is generally made between investment and current expenditures, but again this is not always clear-cut, not least because current expenditures are required to maintain the value of capital assets such as roads and other physical infrastructure. From a farmer's point of view, the purchase of land may represent an important investment in his or her productive capacity, from the perspective of society it simply involves a change in ownership of an asset rather than a net increase in capital stock, as occurs for instance when land improvements are undertaken.