Kapitalinput

Kapitalinput, or capital input, is the stock and flow of capital goods used in production to generate goods and services. It is a key input in economics, alongside labor (and, in some analyses, land). It covers tangible capital such as buildings, machinery, and equipment; and intangible capital such as software, patents, and organizational capital. Financial capital funds investment but is not itself a direct production input.

Measurement and stock: Capital input is typically represented by the capital stock—the accumulated value of physical and intangible capital at a point in time, net of depreciation. Gross capital formation adds new investment; depreciation reduces the stock, yielding net capital stock. National accounts and balance sheets provide data, though quality and utilization vary.

Production and theory: In a production function, output Y depends on capital input K and labor L (Y = F(K, L)). The marginal product of capital (MPK) is the added output from one more unit of capital, holding other inputs constant. With diminishing returns, MPK generally declines as K rises.

Growth and policy: Investment that expands the capital stock supports long-run growth, subject to depreciation and technological progress. In Solow models, higher saving raises steady-state capital; in endogenous-growth frameworks, capital accumulation can influence growth rates. Policy tools include depreciation rules, subsidies, and infrastructure that affect investment incentives.

Limitations: Measuring capital quality, utilization, and the mix of capital types is challenging. Capital interacts with technology, institutions, and human capital, so analyses may misstate its productivity impact if these factors are ignored.