Source: p 594, Economics, 3 Ed, 2014, by N G Mankiw, M P Taylor
Yet further thought reveals a fallacy in this answer. When prices rise, buyers of goods and services pay more for what they buy. At the same time, however, sellers of goods and services get more for what they sell. Because most people earn their incomes by selling their services, such as their labour, inflation in incomes goes hand in hand with inflation in prices. Thus, inflation does not in itself reduce
people‘s real purchasing power.
Is the bolded (independent) clause too presumptuous? I doubt its truth. Even if hand in hand means any positive correlation weaker than 100%, the bolded can be false. For example, despite being in view of inflation in prices, a greedy employer can simply refuse to increase wages. Then no inflation in incomes exists, and so inflation DOES reduce
people‘s real purchasing power?