This book investigates the economic relationships between population, wages and labor productivity. In particular, we aim at studying the demographic link between real wage and population dynamics. An inverse relationship between population growth and wage evolution prevailed during the so-called "Malthusian era", until the Industrial Revolution, when the increased productivity allowed a real wage growth even if the population was rising as well. Empirical evidence confirms this trend in the case of the United Kingdom and, partially, of Italy. However, in Switzerland, it seems that the rise in productivity was not able to counterbalance the downward pressure on wage due to workforce abundance.