To some, the sound of children at play is a bitter irritant. But to German lawmakers, children’s noise is mellifluous. When the Bundestag amended the Federal Pollution Control Act in 2011, exempting day-care centers, playgrounds, and similar facilities from lawsuit-inciting sound ordinances that would otherwise restrict their development and expel them like trades of ill repute to city fringes, the legislation was accompanied by an upbeat appeal: children’s noise (Kinderlärm) is “future music” (Zukunftsmusik).

If that phrase is a sentimental throwaway, its connotations are increasingly various. In the past five years, the regulation of children’s noise has, in ways odd and unprecedented, become bound up with the futures of some of the world’s largest economies—embedded in long-term policy initiatives affecting fertility, maternal employment, gender equality, and urban planning. In Germany and, more recently, Japan and Switzerland, punitive noise laws have come under scrutiny. Parents and youth advocates see the rules as a sign of societal intolerance toward children; governments cite them as impeding and contradicting their efforts to boost birth rates and maintain quality of life.

While people born in these rapidly aging countries are the beneficiaries of very high life expectancies, they first have to endure a childhood at the bottom of an inverted pyramid, their laughs and shrieks the scourge of a grown-up population both less accustomed to and less permissive of such sounds.

Germany’s legislators recognized that if the introduction, in 2013, of universal day care was to have its intended effects (the availability of childcare is a critical factor in people’s decision to have kids), there would need to be 90,000 more places in day-care centers. So in addition to amending the Pollution Control Act’s noise rules, the federal government changed land-use ordinances to permit day-care centers in residential areas.

In Japan, where 43,000 children are currently on day-care waitlists, attention has also turned to sound. Prime Minister Shinzo Abe wants 400,000 more spots by 2018 in an effort to increase the fertility rate and female labor-force participation. The Tokyo Metropolitan Government voted in April 2015 to exempt preschools from noise-pollution rules that cap sound at 45 decibels—similar to levels permitted inside libraries. The city hopes that the new limits will relieve childcare facilities from expensive soundproofing and protracted litigation—and preschoolers from the burden of being hushed.

These changes have not kept kids’ voices entirely beyond reproach, though. Recently, in an affluent neighborhood in Berlin—which in 2010 granted children’s noise the same legal immunity as church bells, emergency sirens, and snow ploughs—a 16-foot-high sound barrier was erected around a day care and playground, instigated and paid for by a neighboring luxury-housing development. Community outrage ensued, and another plea was issued, this time by the director of the German Children’s Fund: “Tear down this wall.”

Uninhibited play, however, is a freedom rarely won without an accompanying financial imperative. Scarcity, more so than sympathy, has secured children their voice. Kids can be kids as long as they are taxpayers someday.