Matthew Connelly recently published Fatal Misconception: The Struggle to Control World Population, a book that has chafed demographers and those working in the family planning sector. If Connelly had foreseen the attention his recounting of the population movement would garner, he might have taken more care to represent more sides of the story. He also might have talked to more living people, especially women, rather than relying so heavily on written archives.

Controversially, Connelly argues that family planning programs in the 20th century were responsible for only 5 percent of the fertility decline experienced during that time. His proof? That fertility levels were already declining before family planning programs began. On page 338, he writes, “Moreover, it could not be shown that even the 5 percent effect was actually caused by such efforts, or whether instead broader socioeconomic or cultural changes explained both the decline in parents’ preference for large families and government willingness to provide them with contraceptives (what economists call the endogeneity problem).”

But examples abound in which fertility declined drastically following the introduction of accessible contraception. For example, after officials in Iran revised the country’s family planning program in the late 1980s, fertility dropped from 5.62 births per woman to just above 2 today. Fertility had been declining since the early 1960s, but at a much slower rate.

In the early 1960s, the fertility rate in Brazil was 6.2. In the years after Planned Parenthood arrived and pharmacies began selling contraceptives, fertility fell to 3.5 births per woman. Today, Brazil’s fertility rate is around 2.35 births per woman, which is close to replacement level.

When women can choose for themselves when to have children, they often choose to have smaller families. The family planning movement has not been perfect, but it has frequently acted courageously to give women the choices they deserve. Its successes should not be overlooked.

Marian Starkey, communications manager at Population Connection, holds a master of science in population and development from the London School of Economics.