However, in much of the developed world, such as in Italy, the population is not increasing but decreasing, and decreasing dramatically. This fact is as revolutionary as it is unheralded. In fact, there is no longer a single country in Europe where people are having enough children to replace themselves when they die. The reasons are complex. Experts agree that decreases can be attributed to a matrix of social, economic, and cultural changes.
Prosperity often leads to lower birth rates.
So does urbanization and industrialization. These days, many women stay in school longer, put more emphasis on work and marry later. As a result, they have fewer children. Only in times of plague, war and deep economic depression have birth rates fallen so low, for so long.