Monday, 9 March 2015

Production function & Cobb–Douglas production function



Production Function
A production function relates physical output of a production process to physical inputs or production. The primary purpose of the production function is to address allocative efficiency in the use of factor inputs in production and the resulting distribution of income to those factors, while abstracting away from the technological problems of achieving technical efficiency, as an engineer or professional manager might understand it.
Production in this way is defined as the transformation of input into output.
Product Function is
            Y = f (L, K, S)
Here Y = Yield (production), L = Labor, K =Capital S= Land
Factor inputs are classified into fixed factors and variable factors.
Where as fixed factors are not related to the level and volume of the profit and these factors remains fixed whether the volume of product is more or less or even zero.
And variable factors are factors which are directly related to the volume of output such as labor, fuel, and raw material.
The distinction between fixed and variable factor is restricted to short period only. In the long period, all factors are supposed to be variable.



 Cobb–Douglas production function
The Cobb–Douglas production function is a particular functional form of the production function, widely used to represent the technological relationship between the amounts of two or more inputs, particularly physical capital and labor, and the amount of output that can be produced by those inputs. In its most standard form for production of a single good with two factors, the function is                                           
Where:
Y = total production (the real value of all goods produced in a year)
L = labor input (the total number of person-hours worked in a year)
K = capital input (the real value of all machinery, equipment, and buildings)
α and β are the output elasticities of capital and labor, respectively. These values are constants determined by available technology.
Output elasticity measures the responsiveness of output to a change in levels of either labor or capital used in production, ceteris paribus. For example if α = 0.45, a 1% increase in capital usage would lead to approximately a 0.45% increase in output.
Further, if
α + β = 1,
the production function has constant returns to scale, meaning that doubling the usage of capital K and labor L will also double output Y. If
α + β < 1,
returns to scale are decreasing, and if
α + β > 1,
returns to scale are increasing. Assuming perfect competition and α + β = 1, α and β can be shown to be capital's and labor's shares of output.