We have known for some time that the world needs more children—more young people to work and pay for the care of a growing population of elderly people who are living longer than ever.

But the world also wants more children. That is, most people across the globe would like to have more children than they expect to have.

That's the main conclusion of a recent survey commissioned by The Economist magazine. The poll, conducted by Globescan, surveyed people in 19 countries, asking them how many children they'd like to have and how many they expected to have. In every rich country, people expected to have fewer children than they wanted. Many people in poor countries felt the same way.

Majorities of people in 11 of the 19 countries surveyed are not having as many babies as they'd like. Among them are the U.S., Australia, Greece, Britain and Russia.

Just 52 years ago, the average woman gave birth to 5.1 babies. Today, the average is less than 2.5 babies per woman. This decline is the result of, among other things, delays in marriage until later ages, the near ubiquity of birth control, legal abortion and changing mores in which women in many countries are no longer prevented from or shunned for prioritizing education and career over childbearing.

Money is a major factor preventing people from having as many children as they'd like. As The Economist reports, "From Brooklyn to Beijing, the cost of housing and education is so high that many young people say they cannot afford as many children as they want." Economic insecurity among young people in developed nations has kept many from starting families since the global economic downturn began nearly a decade ago.

Public policy solutions such as cheaper housing and more family-friendly leave policies would seem to be part of the solution. The Economist also points to more medical innovation in the area of reproductive technology such as In vitro fertilization, which for most people on earth is either unavailable or prohibitively expensive.

But what's most needed is a shift in the paradigm through which policymakers view family planning and population issues. As The Economist puts it, "Governments and aid agencies have turned family planning into a wholly one-sided campaign, dedicated to minimizing teenage pregnancies and unwanted births; it has come to mean family restriction."

Activists and demographers from Thomas Malthus and Margaret Sanger to Paul Ehrlich have predicted that rising birth rates would lead to overpopulation and catastrophe as food production and agricultural innovation failed to keep pace with population growth and governments simply couldn't feed all their people. But the dire predictions of the Malthusians simply haven't occurred, and world economic production has easily outpaced consumption.

Some governments are finally beginning to reform their population policies. In China, where the fertility rate has declined to 1.6 per woman (that is, about 20 percent below the replacement rate), the government recently revised its one-child policy, allowing all couples to have as many as two children.

In its survey, The Economist also found that access to birth control "is seldom much of an issue. Few young people will have more children than they want because reliable contraception was not available to them." In fact, only 6 percent of people under age 35 who had more children than they wanted said that they had failed to use birth control or that it was unavailable, whereas 21 percent of people aged 55 and older cited lack of reliable contraception. The Economist concludes that, "more suffering is caused by having to few babies than too many."

Interestingly, in some countries, having more babies than they think is ideal actually makes people happier. In the United States, 39 percent "of people who reckon they will exceed their ideal number of children report that they are more satisfied with life as a result." Just 8 percent feel sorry for themselves.

The lesson here is not that the government should get out of family planning altogether. Rather, it is that family planning is about much more than birth control. In fact, in many countries, both the official policy and the personal habit of limiting births has led people to decisions they now regret.

Daniel Allott is deputy commentary editor for the Washington Examiner