Final answer:
Contraception is the most universal method used by governments to control birth rates. It comes in various types, such as barrier methods, hormonal methods, intrauterine devices, behavioral methods, and sterilization. The effectiveness of these methods is measured by failure rates, and most are reversible except for sterilization.
Step-by-step explanation:
The most universal means used by governments to control birth rates is contraception. Contraception is the prevention of pregnancy by preventing the sperm and egg from joining, and it is a widely employed method for controlling birth rates. More than half of all fertile couples globally use some form of birth control. The effectiveness of these methods is often indicated by the failure rate, the percentage of women who become pregnant in the first year using a specific contraceptive method.
There are several types of birth control methods including barrier methods like condoms and diaphragms, hormonal methods such as the pill, intrauterine devices (IUDs), behavioral methods like fertility awareness, and sterilization. Most methods, with the exception of sterilization, are reversible. Barrier methods can also prevent sexually transmitted infections as well as pregnancies.
Emergency contraception, such as the 'morning after' pill or insertion of an IUD, can be used after unprotected sex to prevent pregnancy.