GDP Made Simple

Just a few weeks ago, the U.S. Government’s Commerce Department provided its first estimate of the country’s 3rd quarter (July-September 2009) gross domestic product or GDP, announcing an estimated annualized quarter over quarter growth of 3.5%. GDP reports are of special interest to countries since they provide an important macroeconomic measurement of how much an economy’s goods & services supply and income has grown, or recessed, compared to the last three calendar months.
Let me try and make the concept of GDP easy to understand and why it is considered perhaps the most important, single macroeconomic measurement.
GDP is simply a calculation that measures the market value (final price) of all the final goods and services produced within the borders of our country. Thus, U.S. GDP includes Toyotas produced in Alabama but excludes Cadillac’s made in Canada. GDP includes all U.S. exports but excludes all U.S. imports since imports, by definition, imports are produced in some other country and are a more direct employment benefit of the foreign country’s GDP.
If you think about it, ultimately our country’s economic satisfaction is best measured by the goods and services that are produced and that we have access to, which is why GDP is the measurement that is synonymous with “economic growth” or growth in goods & services for its citizens. In addition, rising GDP (more goods and services) is the ultimate economic goal of any economy which can best be accomplished through the means of the two other key macroeconomic measurements of employment and productivity, which are not the subject of this particular blog.
Let’s describe how the GDP calculation is made. Each quarter, the Government compares the final value of the domestic goods produced and services rendered in the current quarter to the final value of the goods produced and services rendered in the previous quarter. The calculation then takes the percentage gain, current quarter versus previous quarter, and annualizes the percentage. The comparison is always restated for inflation so that the figures are comparable from one period to the next. For purists, we call this “real GDP” which is the only GDP reported by the media, even though the word “real” is almost always dropped to avoid confusion with the average citizen. For example, the third quarter 2009 U.S. GDP report highlighted a 3.5% GDP annualized growth rate. This means that the second quarter final value of goods and services produced was approximately .87% or 3.5%/4.
Now let me get to my favorite point on GDP, which even many economists lose sight of. GDP growth is precisely the same as income growth! For example, in the second quarter of 2009 we can say that incomes for American households and American citizens grew by 3.5% restated for inflation. Said another way, our country’s purchasing power grew by 3.5% which represents the income to produce the increasing supply of goods and services. You probably never thought about it this way but every time you purchase something, every dollar you spend is going to someone as income, whether it is the workers as wages or benefits, the landlords as rent, a bank that has made a loan as interest income, or to the owners of the business as profits. I tell my students that Real GDP = Real Income and the only question is how that real income is dispersed among owners (profits), workers (employee wages and benefits), lenders (interest), and lessors (rent). Many citizens are unaware that the Government calculates GDP both in terms of the final market value of the goods and services PRODUCED (the “expenditure method”, which is the version that the media uses, as well as how that same production value under the “expenditure method” translates to higher incomes in a GDP version called the “income method”.
I find the preceding paragraph, GDP = Income, to be a break through moment for a lot of citizens, or first time economic students, in truly understanding the value of the GDP measurement. It is easier for most to think in terms percentage growth in income in lieu of a fuzzier wording like GDP percentage growth. Most citizens are surprised to find that our national incomes or GDP, restated for inflation, increased by 17.4% from 2000 – 2007, just prior to the onset of this current recession. This 7-year growth rate in GDP or incomes still equates to a below average historical average performance. More specifically, over the last 7 years our average annual GDP or income growth rate was only 2.2% versus our historical average growth rate of 3.2%. However, the final point of caution is that the GDP or income growth rate is a collective average, thus the growth in GDP or incomes does not indicate how those income gains are accruing to the various socioeconomic classes or professions. That is also a topic of a future blog on “income distribution” or equality.
Discussion Questions:

1. Have you ever thought about substituting the word “income” for “GDP” to understand GDP more simply? Why are the concepts of income and GDP inter-changeable?
2. Which four groups earn the income generated by the production of goods and services?
3. Although GDP has still risen this decade, despite the current severe recession, many analyses show that our nation’s middle class has made virtually no real income gains this decade. How could this be so if GDP = Income and our GDP has grown this decade?