Calculation formula of elastic coefficient: ε= -(△Q/Q)/(△P/P)= -(P×dQ)/(Q×dP).
Elastic coefficient is the ratio of the growth rates of two interrelated economic indicators in a certain period, which measures the dependence of the growth rate of one economic variable on the growth rate of another. From the calculation method, the elastic coefficient can be divided into nominal elasticity and actual elasticity.
For example, investment elasticity coefficient and consumption elasticity coefficient are the ratio of economic growth rate to investment demand growth rate and consumption demand growth rate, which respectively reflect the elastic effects of investment growth and consumption growth on economic growth, indicating how many percentage points each percentage point of investment and consumption growth can drive economic growth.
From the calculation method, the elastic coefficient can be divided into nominal elasticity and actual elasticity.
Nominal elastic coefficient is the ratio of speed calculated from the present value of relevant indicators; The actual elastic coefficient considers the price factor, which is the ratio obtained by using the constant price or the speed calculated after deducting the price factor.
Elasticity in economics refers to the sensitivity of changes in one variable to changes in another. Elasticity can be measured by elastic coefficient, and elastic coefficient = Y change percentage /X change percentage.
The concept of elasticity in economics was put forward by alfred marshall, which refers to the property that one variable changes in proportion to another. The concept of elasticity can be applied to all variables with causality. The variable as the cause is usually called the independent variable, and the quantity changed by it is called the dependent variable.
For example, there is a relationship y = f(x) between the independent variable x and the dependent variable y, then the x elasticity of y: ey/ex = (△ y/y)/(△ x/x) = f' (x) x/y.
In western economics, elasticity refers to the reaction degree of consumers and producers to price changes.
In economics, the general formula of elasticity is: elasticity coefficient = rate of change of dependent variable/rate of change of independent variable.
Extended data:
The tax elasticity coefficient is defined as the degree of tax response to economic growth, that is, the ratio of tax revenue growth rate to economic growth rate, and its formula is:
ET=(△T/T)/(△Y/Y)× 100%
In the formula, ET is tax elasticity, T is total tax revenue, △T is tax revenue growth, Y is GDP, and △Y is its increment.
According to the above formula, ET= 1 means that tax revenue and economy grow simultaneously; When ET> is 1, it shows that the tax revenue growth is faster than the economic growth, and the proportion of tax revenue participating in the new national income distribution has an upward trend; Eastern （Standard） Time
Price elasticity of commodity supply refers to the degree to which the change of commodity supply responds to the change of commodity price in a certain period. Its value is equal to the ratio of supply change rate to price change rate, which is generally expressed by supply elasticity coefficient.
Price elasticity of commodity demand refers to the reaction degree of demand change of a commodity to the price change of the commodity in a certain period of time. Its value is equal to the ratio of demand change rate to price change rate.
References:
Baidu encyclopedia-elasticity coefficient