For another exapmle for PMSElle, take population.
If people live healthier lives, they live longer. A longer lifespan is linked with a lower birthrate, and also a better standard of living AND education AND gender equality. When you're in school you're less likely to have babies, so the avg age of new parents increases. When this happens the interval between new generations of babies is increased and the population drops. ALso, when women have more rights and access to contraception and such things, she has more choice as to when to have kids. ALso educated couples tend to put their careers and standard of living higher on their priority list, and thus delay having kids, or have less kids. Also, a better standard of living makes it easier to to have access to doctors, and healthy foods, so people tend to live longer. As humans, in every population we see that when death rates decrease, birth rates also decrease to match. So longer living and health is linked to shriking populations.
In truth, the human population won't continuously grow. It is scheduled to plateau at about 10billion in 2050. The reason we had the big boom was because of new discoveries in medicine and public health.
THEREFORE: if you're a doctor, a teacher, a gender equality activist, a contraception provider, a nutrition provider (farmer) and all the other possible related careers, that is all a priority for healthy population maintainence.
