Q.'What is true for a single individual need not be true for the economy as a whole.' Explain this statement with the help of the paradox of thrift.

This is the 'fallacy of composition' — a conclusion valid for one unit can be false for the whole economy, illustrated by the paradox of thrift, where everyone saving more can reduce total saving.

The statement expresses what economists call the fallacy of composition — the error of assuming that what is true for a single individual unit must also be true for the economy as a whole. Because macroeconomic aggregates are interconnected in ways that individual decisions are not, a conclusion that is perfectly valid at the micro level can be false at the macro level. This is one of the main reasons Macro Economics must be studied as a separate branch, and not merely as micro-economics scaled up.

The paradox of thrift is the classic illustration. At the level of a SINGLE household, saving more is clearly beneficial: if one family cuts its spending and saves a larger share of its income, its wealth grows and it becomes better off. It seems natural to conclude that if saving is good for one household, more saving by EVERYONE must be good for the economy.

But consider what happens if ALL households try to save more at the same time. The key macroeconomic fact is that one person's spending is another person's income (the circular-flow insight). When every household cuts its spending to save more, the total demand for goods and services in the economy FALLS. Firms, facing lower sales, cut back production, lay off workers, and pay out less in incomes. As incomes fall across the economy, households find they can no longer save as much as they intended — and total saving in the economy may end up NO HIGHER, or even LOWER, than before. The very attempt by everyone to save more has reduced the total income out of which saving is done. …

Students sometimes explain the paradox of thrift as simply 'saving is bad', which misstates it — saving is beneficial for an individual and necessary for investment; the paradox is specifically about the effect of EVERYONE trying to save MORE …