Why countries have longer life expectancy and lower birth rate?

Countries with longer life expectancy and lower birth rates often have advanced healthcare systems, better nutrition, and higher living standards, which contribute to overall health and longevity. They also tend to have greater access to education and family planning resources, empowering individuals to make informed decisions about reproduction. Additionally, socio-economic factors, such as urbanization and women's participation in the workforce, often lead to delayed childbirth and smaller family sizes. These elements collectively shape demographic trends, resulting in longer life spans and reduced birth rates.