Autor: Bruce, Anderson and McShane, Philip

Buch: Beyond Establishment Economics

Titel: Beyond Establishment Economics

Stichwort: Lonergan, Maniw: Messung vs. Imagination

Kurzinhalt: 6.2.2 Different Mentalities: Measurement versus Imagination. Supply & demand are key elements in Mankiw's analysis yet he does not provide any measurements of them in his discussions

Textausschnitt: 6.2.2 Different Mentalities: Measurement versus Imagination

120a Lonergan & Mankiw have different positions on what counts as fact in the field of economics. This difference can be illustrated by examining how they treat measurement. Lonergan's view is straight-forward. In order to find out what is going on in an economy the significant economic variables must be measured. The mentality of Lonergan is that of a scientist. The rates of payments in the monetary circuit must be measured. There is no room for speculation or predictions in his analysis. This requirement means that we need new types of measures than those that currently exist if we want to understand what is going on in an economy. For example, the different charges levied by telephone & power companies and banks on ordinary consumers and corporate clients would need to be extended throughout the economy in a way that recognized the distinction between surplus goods & services and basic goods & services. It takes more than a little thinking to reveal the massive size of this challenge. (Fs)

120b By contrast, Mankiw's treatment of measurement is much looser. Mankiw does not share Lonergan's empirical mentality. Supply & demand are key elements in Mankiw's analysis yet he does not provide any measurements of them in his discussions. Of the 180 graphs in Mankiw's book only 27 graphs1 draw on measurements or data that were actually gathered. Of the many tables in his book, the only actual measurements provided are in tables found on just 7 pages.2 The remaining graphs and tables appear to be made-up or invented. You might argue that because the graphs in the book are meant to communicate complex ideas that it is legitimate to invent them. However, I disagree.3 My point is this non-empirical, non-scientific attitude can easily allow authors & readers to slip into a perspective where they no longer notice the difference between what actually occurred and what is imagined. The very serious problem is that this habit can lead to analyses & explanations in textbooks that are not relevant to what actually happens. Mankiw's textbook falls into this trap. (Fs)

121a As I see it, the absence of measurement means there is insufficient evidence to support the many claims Mankiw makes about the economy. Take the notion of total surplus, one of the legs of comparative advantage, as an illustration. The calculation of the consumer surplus rests, not on an empirical measure, but on what someone was willing to pay - but did not actually pay - for particular goods. The result is that total surplus, and hence the argument and judgment that trade makes people better off, rests on speculation, not facts. (Fs) (notabene)

121b To be more specific, Mankiw's portrait of the model of supply & demand - for goods, for loanable funds, for money, for foreign-exchange currency - falls into this trap. Measurements are missing from these analyses. The absence of measurements in this context undermines the effort to understand how the economy works. Measurements will help us judge whether or not the explanations of supply & demand are accurate descriptions of what actually happens. As they currently stand, these models have not been tested. This situation is serious enough to raise doubts concerning their adequacy as explanations of how an economy works. (Fs)