Purpose and Measurement of National Income and Product
Atkinson, Glen, Journal of Economic Issues
A careful examination of the construction of national income and product accounts provides remarkable insight into professional and popular thought about the operation of economic processes and activities. According to Simon Kuznets, the father of national income accounting in the United States, "being thus a summary and appraisal notion rather than an analytical entity, national income demands statistical measurement" (Kuznets  1951, 3). Kuznets quickly warned "further investigation reveals, however, that the clear and unequivocal character of such estimates is deceptive" (Kuznets  1951, 5). He then discussed the myriad of theoretical and practical issues that are encountered when one sets out to measure the economic activity of a nation. Modern students of the economy would benefit greatly from studying this article by Kuznets to understand the preconceptions that provide the foundation of the seemingly objective measurements of economic activity.
As Nelson Peach expressed it, "the kinds of activities included in National Income depend on value judgments of what is and what is not productive. Traditions, customs and mores of the community shape these judgments. Items that are included in it are different from country to country and they change over time" (Peach 1964). This statement caused me to ponder the meaning and relevance of national income accounting for the intervening forty years.
It is my objective to examine the development of a few of the major accounts and selected components of these accounts to reveal some of the judgments that were important in creating our view of economic relations. Our habitual assumptions shaped the accounts, which in turn tended to solidify our assumptions. My purpose is not to discourage quantification or the use of these accounts. In fact, institutional economists were pioneers in developing national income accounting. My point is to encourage our colleagues to reinvestigate the assumptions that provide the foundation of national economic accounts so they do not get lost in the mist of history. Furthermore, we will show that each accounting method was developed to assist in understanding a particular problem, such as social unrest, depression or war. The purpose has to be appreciated before we can understand the measuring tool. Perhaps this generation of institutional economists could develop new quantitative accounts that would provide insight into today's economic problems. At the very least, we could develop adjustments to existing accounts to correct for mistaken or out of date assumptions. According to Peach, "generally only current, productive, legal, economic activity that goes through the market is included" (Peach 1964), thus our meaning of national income is constantly changing.
The structure of our economy is also changing and this requires either adjustments to the structure of the accounts or care in interpreting the data. One simple illustration out of many cases provided by Kuznets ( 1951, 32-33) is the effect of the diminishment of the proprietor form of business organization and the growth of the corporate enterprise. Along with this transformation, employment in agriculture was in decline as manufacturing employment increased. During the period observed by Kuznets, labor's share of income was stable. But that hides the fact that many small businessmen and farmers were removed from the proprietor class and became wage earners instead. Hence, wage earners accounted for a larger portion of the productive population but, as a class, they received a constant slice of the income.
In the next section, I will discuss the historical context and purpose that drove the effort to create the measure of National Income. That is followed by a discussion of the reasons to shift from National Income to Gross National Product. (1) Next is a section that examines the introduction of the income and product accounts into modern introductory textbooks. …