The dynamic study of human populations has become a useful tool in the service of population and social policies in numerous countries, in areas such as social security systems and economic employment.
Thus, governments use demographics to determine a country’s growth and the impact of public service provision on its population. When we speak of the de facto population, specifically, we refer to the number of people present and transients—that is, those who, despite not being registered in the municipality where the census is conducted, are in that location at the time it takes place.
The welfare state can be defined as the set of policies consisting of the universal implementation of public and social services that are not economically profitable for the private sector. These services aim to maximize social benefit, guarantee adequate living conditions for the population (education, healthcare…) and prevent people from being left helpless in certain problematic circumstances (retirement, illness, disability…). The state guarantees more or less universal access to these services. It is usually financed through taxes in order to contribute to a true redistribution of wealth.
Generally, several types of benefits can be distinguished:
• Universal benefits, which are offered to the entire population free of charge and only require the beneficiary to request them. For example, healthcare or compulsory education.


