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Showing posts from February, 2025

Fallacy of Composition: A Keynesian Cross in the Consumer Choice

  Come to think of it, there in the corner of economics is a hidden cross, utile or useless.   The Cross in Consumer Choice. For the purpose of giving some sense to the so-claimed “price” of x good ( p x ) in the consumer choice model, certain economists put the budget for “all the other goods” on the y axis (e.g. Samuelson and Nordhaus 2010, p.88; Hal Varian 2010, p.114). In this case, the total household income becomes the budget constraint.              Alas, they fall prey of fallacy of composition Paul Samuelson talked about as early as in 1948 ( Economics , p.9). Suppose apples on the x Axis of John Doe’s coordinate, and the weekly income on the Axis of y . Further suppose that the apple sells @ $0.5 and that Doe’s income, or spending budget, for all purposes is $5,000.              Question 1 : How many units of apples could Doe buy per week,...

Fallacy of Composition: A Keynesian Cross vs Another on the Road

  When you come across a fork on the road, what are you gonna do? Take it, or so says Yogi Berra . What if a cross on the road? Just take it, stupid, or so would Berra say. What if it’s a Keynesian Cross ? Umm……, please ask someone else, or so would even Yogi say. .              Many innocent students of macroeconomics have hard time understanding the Keynesian Cross. Don’t worry; be happy, “You are not alone.”              Generally speaking, macroeconomics is for the heavens; naturally, it is not only unknowable to each student but also arcane to the rest of us all. Particularly, we’ll never know what the shiny “Keynesian Cross” is like until post mortem . We begin with another lackluster cross.   The Cross in the Market. Probably, most finance-savvy high-school students of modern times are well aware of the demand and supply curves.   ...

Fallacy of Composition: Their So-called Budget Constraint

  All the celebrated ideas of indifference curves, isoquants and production possibility frontiers are associated directly or indirectly with a “ budget constraint .” The budget may in terms of a good, money or two production factors.              Interestingly, however, the budget constraint is of no use either in the market or in the economy. More specifically, the constraint is irrelevant to the market while redundant, or “nominal” as used in macroeconomics, in the economy.   No Constraint to the Market. To begin, the market is imagined for a particular product traded in a bounded community over a defined period of accounting. Otherwise, we cannot think   of the equilibrium price ( p* ) and the quantity traded ( q* ), much less naming them.              By nature, the product is merely one of indefinitely many goods and services wanted by t...

Fallacy of Composition: No Backtracking in the Market

  For better or for worse, we are born with limited physical and mental capacities vis-à-vis unlimited desires of indefinitely many kinds. Providentially, we have to gratify each desire bit by bit every once in a while. Yes, consumption of goods and services is periodical while we are in Here.              On the other hand, nothing pleasant to consume comes for free. Consequentially, we have to produce utilities, necessary or desirable, directly or indirectly, and that also periodically. In modern times, our life is communal as well as private; we spend some time in the public arena producing some things potentially utile and consuming other actual utilities. Particularly we trade periodically in the public market of consumable products on one hand and creative services on the other.              Now, a clear definition, may it be implicit, of the accountin...

Fallacy of Composition: Income vs. Leisure

  Economists are sometimes confused between friends and foes. For instance, Gregory Mankiw proposes “the Trade-off between Work and Leisure” ( Principles , Ch.18): Alas, one of the three capitalized words is misplaced. As far as the rest of us understand, “Trade-off” is a choice between two competing benefits or two opposing costs .              Are Work and Leisure competing? Sorry, we don’t think so: With no hesitation at all, we do unanimously vote for “leisure.” See, work is a “pain” while leisure is a “pleasure.”              According again to Gregory Mankiw, incidentally, “The Cost of Something is What You Give up to Get It” (Ch.1). “Something” being beneficial, the Cost must accompany a Benefit. Eureka, a benefit and the cost are friends! On the flipside, we cannot eat the cake and have it too. Eureka, a pleasure at present and another in the future a...

Fallacy of Composition: Indifference Curve and PPF

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  The market as featured in economics is a typical microcosm out of indefinitely many markets for trade in goods, services, rental rights, physical or intellectual assets and credits or other financial instruments. By conception, there in each and all the markets surely is the unit of account (U), such as $, €, ¥ or ₤, dictated by the sovereignty.              Moreover, there on each side of demand or supply is absolutely no budget limit to each and all participants. Each item such as the apple takes the infinitesimal , so to speak, out of the whole budget for all the utilities of various disguises of all the members of each household; the same for all the participating households in the market of the community.              Here we make a thought experiment, or a scenario game of imagination. We apply the market logic to the consumer choice model et cetera ...

Fallacy of Composition: Chimeric of Variable and Parameter

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A great problem of economics is an abundancy of misnomers, misleading, oxymoronic or outright deceptive. One out of so many is the so-named “exogenous variable.” It should be called parameter instead. The two of “variable” and “parameter” are different species, period.              By definition in mathematics all variables are endogenous , or internally related. On the contrary, a parameter is external, or “exogenous” to the intrarelationship. By practice in mathematics, in addition, all variables and parameters go naked, with no dimensions of any kind and no scales of any degree. Neither a specific name nor a title, either. By the wayside, such names as “dependent” and “independent” of variables are sheer “in name only”: equations are silent to the causality of science.                 As opposed to mathematics, the nature and the economy have dimensi...