Iran’s post-revolution generation is the largest baby boom in Iran’s 5,000-year history. Its twentysomethings were born during a decade-long blip between two ambitious family-planning programs. During his final decade in office, the shah promoted birth control use. By the end of the 1970s, 37% of women practiced family planning.

After the 1979 revolution, the ruling clerics reversed course and called on Iranian women to breed an Islamic generation. In a decade, the country's population almost doubled (from 34 to 62 million). But the theocracy couldn’t feed, cloth, house, educate, or eventually employ swelling numbers — and voters. So it launched a free birth control program, including required family planning classes for newlyweds. By the 1990s, the average family fell from six children to less than two — lower than during the monarchy.

From New Security Beat: "Following the 1979 revolution... half of the population lived in rural areas, which typically constrains access to health services. In addition, abortion was illegal in most circumstances. According to the UN, Iranian women had an average of 6.5 children each in the early 1980s and the population was growing nearly four percent annually, a rate high enough for it to double in 19 years. But, by the early 2000s, Iran’s fertility rate had dropped below two children per woman."

By actuarial standards, Iran’s baby boomers will have disproportionate clout for at least the next half century on most aspects of Iranian life. Politically, their impact could even be more enduring than the current ruling theocrats.