Skip to main content

Macroeconomics: Gross Domestic Product (GDP)

As we previously saw, the circular flow model shows that all the spending in an economy will roughly equal all of the income received.
  • Every dollar spent on goods or services is money earned by either firms or household. Thus, a nation's total expenditure is equal to the nation's total income.
  • Everything bought was at some point was produced, a nation's (domestic) output is equal to national (domestic) income.
There are three methods for measuring a nation's total output:
  • Expenditure approach
  • Income approach
  • Output approach
Expenditure approach for estimating GDP:
  • Summing the spending on final new goods and services in a given year.
  • Final goods are ready for consumption. Goods used as input in order to produce another goods are not included (only the final product/good is).
There are four types of spending in a nation's output:
  • Consumption(C): spending made by domestic households on durable and non-durable goods and services in a given time.
  • Investment(I): spending by firms on capital equipment and by households on newly constructed homes.
  • Government spending(G): the government's expenditure on goods, services, and capital. Transfer payments are not included.
  •  Net exports(Xn=X-M): total income earned by the sales of exports minus total amount spent by domestic households and firms on imported goods and services.
   
Income approach for estimating GDP:

Estimates GDP by summing the income of households in the resource (factor) market. Remember that national output equals national income.
  • Wages: the payment households receive for providing labor, this also includes salary.
  • Interests: the payment for the use of capital by firms. Most of capital spending is paid for with money borrowed from banks. The money in banks is in part derived from household's savings.
  • Rent: the payment households receive in exchange for the use of their land.
  • Profit: residuals after a firm deducts its costs of production from its revenue. In our case, revenue can be defined as price  times output.
Output approach for estimating GDP:

The output approach sums the total value of all final goods and services produced by a country in a year.
  • This method sums the value of total output for various industries/ economic sectors.  One can find the value of total output by summing the output value for each sector of a nation's economy. This gives us the gross national product (GDP).
Notice that all three methods achieve the same result: GDP=national expenditure= national income. Furthermore, notice that for each method, imports (or foreign produced goods and services) are excluded from our calculation. For more information about this aspect I would suggest reading this article by Steven M. Suranovic.

Reference: Welker, Jason. AP Maroeconomics Crash Course. Research & Education Association (2014). p 64-69.

Comments

Popular posts from this blog

Macroeconomics: multiplier and crowding out effects

Multiplier effect: whenever   any of the components of AD increases, the increase in GDP will be greater than the initial increase in expenditures. The impact on GDP of a particular increase in spending depends on the proportion of the new income that is taken out of the system to the proportion that continues to circulate in the economy. The multiplier effect tells us the impact a particular change in one the components of AD will have on the total income (GDP).  Let k denote the spending multiplier, which is a function of MPC and MPS. The larger the marginal propensity to consume, the larger the spending multiplier. Notice that the larger the MPC, the greater the impact a particular change in the spending variables will have on the nation's GDP. The crowding out effect: If government spending increases without an increase in taxes, the government must borrow funds from the private sector to finance its deficit, thereby increasing the interest rate. This increase in interest ...

Microeconomics: Firms and cost in the short run

In Economics, the term short run refers to a time period where at least one variable of interest does not change . In our case, the short run for a firm is when at least one input  (labor, land, capital) stays fixed. Usually land and capital are considered fixed in the short run.  If an input is fixed during a period time, no matter how much the total product a firm produces, its cost stays the same. This cost is commonly known as fixed cost (FC). Examples of fixed costs: rent, property taxes, loan payments. Labor is often considered to be a part of the  variable cost (VC) . Variable cost can be defined as the cost a firm has control over during the short run. Unlike fixed cost, variable cost increases (decreases) as a firm's total product increases (decreases). Examples of variable costs include: utility bills, wages, raw materials A firm's total cost (TC) is the sum of its variable and fixed costs. As you can see, the fixed cost...

Microeconomics: Factor Markets

Definition: Factor markets: markets for the factors of production (example: labor and capital). Markets are formed whenever consumers and producers meet to exchange goods or services. Deriving factor demand: the demand for goods or services in the product markets creates demand for the factors of production.  An increase (decrease) in demand for good X leads the suppliers to increase their production thereby increasing (decreasing) the demand for the factors of production.   Marginal revenue product: The demand for the factor of production is formed by multiplying a firm's marginal revenue by its marginal product.  Remember that by taking the derivative of the TR function with respect to Q we are able to find the MR. Marginal product on the other hand is found by taking the derivative of the production function with respect to a factor of production (L or K for example). Marginal revenue product (MRP): the change in total revenue when one more input is employed. It decrea...