It took the human race until the year 1804 to reach a world population of 1 billion. A mere 207 years later, 7 billion people will inhabit the planet we call home. This year, World Population Day allows us to focus attention on the effects growing populations have on the environment, the availability of natural resources and perhaps most importantly, the health of women and children.

USAID conducted studies across 29 countries and concluded that investments in family planning multiply the impact of the US foreign assistance budget and a country's own development spending. For example, in Zambia, every one dollar invested in family planning saves four dollars in other development areas including education, water sanitation, malaria, immunization and maternal and child health.

"Investing in family planning is cost-effective and essential to solving many health and development issues," said USAID Administrator Rajiv Shah. "When an individual or a couple has the ability to choose the timing and spacing of their children, they are better equipped to provide for their family's well-being."

As the largest international bilateral donor in family planning, USAID commemorates World Population Day by celebrating its more than 45 years as a world leader in supporting voluntary family planning programs in developing countries. US funding for international family planning programs is integral to achieving President Obama's Global Health Initiative goals. USAID collaborates with other U.S. government agencies to reach the target of preventing 54 million unintended pregnancies. Enabling young women to avoid early pregnancy allows many to attend school longer, and as fertility falls, join the labor force. Increased family income means more money is available to spend on children's education and nutrition, launching a cycle of opportunity and breaking from a cycle of poverty.

To learn more about World Population Day, please visit the event page on the USAID website.