Many of America's cities are gaining population, but the number of school-aged children is dwindling as families opt for the suburbs.

Why it matters: A growing body of research shows the strong link between the environment where kids grow up and their ability to thrive as adults. Yet the gap between the haves and have-nots is becoming more pronounced in city centers, driving middle-class families out.

• Neighborhood divides: Nearly 10 million American kids live in low-opportunity neighborhoods, with limited access to quality schools, parks and healthy food.
• Child care deserts: About half of Americans live in communities where there are not enough licensed child care workers to meet the demand. In Tulsa, Oklahoma, and Mobile, Alabama, the child care market can only serve one-third of the total young children.
• Housing: In most big cities, there's a shortage of housing options for middle-class families as rents increase.

By the numbers: In 2018, about 12% of children 17 and under lived in the central or principal city of a metropolitan area, down from 14.6% in 2010.

• The percentage of children 5 and under in central cities dropped from 16% in 2010 to 13.9% in 2018, according to the Census Bureau's American Community Survey data.

Zooming in: In Boston, the population of school-aged children has dropped by nearly half since 1970, per a report by The Boston Foundation. Even though the city has gained about 46,000 new households in the past 40 years, just 1,000 of them have children.

• Paul Grogan, CEO of the nonprofit, said in the report that Boston now seems to be split in two: "One of higher-income, less diverse, childless households, and the other of low-income, largely Black and Latino families in which the vast majority of the city's children live."

Government programs that target children yield higher returns on investment than programs geared toward adults, according to research by Harvard University economists Nathaniel Hendren and Ben Sprung-Keyser, who studied 133 federal and local policy changes.

• What they found: Direct investments in low-income children's health and education pay for themselves and offer more return for each dollar than many programs for adults.
• Investment in adult services can pay off "if those policies have positive spillover effects on children," they write.

The business case: Some local governments are partnering with the private sector and philanthropies to fill funding gaps for education or health programs, and even financing for parks.

• "If we don't have more high schoolers graduating who want to stay in Kent County and work in Kent County, we're going to go bust," said Wayman Britt, county administrator of Kent County, Michigan, which includes Grand Rapids.

What to watch: Children are among the hardest to count in a census, especially those under 5.

• Ensuring high response rates among families is key for communities to receive millions of dollars in federal and state funding for children-specific programs and services.

Go deeper:

• America's hardest places to grow up
• The striking upward mobility gap between black and white men

Communities are starting to prioritize pre-kindergarten programs to boost children's school performance — as well as to provide quality child care for parents who work.

Why it matters: "This is more than just an educational issue. It's a public health issue, an economic and workforce development issue, and a child poverty issue," said Olivia Allen, project manager at the Children's Funding Project.

• Research has shown children who aren't prepared for kindergarten fall behind by the time they reach third and fourth grades, which is when states start accountability testing.
• But the average preschool tuition for two children costs 20,000 per year — about a quarter of the median family income.

By the numbers: Nationally, 33% of 4-year-olds and 5% of 3-year-olds were enrolled in state-funded preschool in the 2016–2017 school year, per the National Institute for Early Education Research.

In Texas, half-day pre-K programs were available for households with incomes below 185% of the poverty threshold. But it wasn't workable for families that needed full-time care.

• In 2011, San Antonio voters approved to raise the local sales tax by one-eighth of a percent to expand full-day pre-K for 4-year-olds across the city.
• Sarah Baray, CEO of Pre-K 4 SA, said their research found "children had better reading and math scores, significantly better attendance, and were far less likely to need special education services."

Pre-K programs have also been shown to help mothers re-enter the workforce.

• In 2009, the District of Columbia began offering two years of universal, full-day preschool to 3- and 4-year-olds.
• The Center for American Progress attributed a 10 percentage-point rise in maternal labor force participation to the preschool expansion.

The big question for most cities is how to pay for preschool programs. Cobbling together enough money to pay teachers a living wage continues to be a challenge.

The good news: "Once it's there, it's not an area where either political party looks to cut," said J. Ryan McMahon, county executive of New York's Onondaga County, which includes Syracuse. "If you can prove metrics, you can have good results."

Parents are pressuring their communities for better preparedness, resources and action plans to keep their children safe in schools, Axios' Marisa Fernandez writes.

Why it matters: Deadly school shootings in the U.S. are on the rise.

Between the lines: To help prevent violence, most districts are focused on protecting students who are suicidal and helping students deal with conflict.

"It’s really the connection that the students have with the people in the school that really make a difference when you look at prevention."

The big picture: Most of the 250 relevant bills introduced across the U.S. address physical measures like metal detectors or law enforcement officers.

• Some state and local legislatures are working with school districts to address students' emotional and mental health needs.

What they're doing:

• Texas has been funneling more money into schools for safety measures. Its Frisco school district purchased bulletproof glass, lockdown technology and mental health teams, the Dallas Morning News reports.
• Florida Gov. Ron DeSantis issued an executive order in February requiring a state review of schools' discipline diversion programs, the Tampa Bay Times reports.
• The Trump administration worked with families affected by the Parkland, Florida, school shooting and launched schoolsafety.gov.

The bottom line: Parents ranked school safety the top priority over several academic opportunities like AP testing and tutoring, the Dallas Morning News polled in December.

Go deeper: USDA proposes letting schools sub grains, meats for veggies

An overwhelming majority of schools in the U.S. lack nurses and counselors to help students in need, per a 2019 ACLU report from Education Department data on every school district, writes Marisa.

Why it matters: Children are reporting just as much stress as adults, with one in three admitting to feeling depressed.

• Students are 21 times more likely to visit school-based health centers for mental health than community mental health centers.
• Especially in low-income districts where resources are scarce, these mental health providers at schools can be a district's first line of defense.

Go deeper: U.S. schools prepare for coronavirus spread

Axios' Kia Kokalitcheva reports: When startups set out to become the “Uber for kids” several years ago, they predicted parents would use them to ferry children to and from school and activities — but they’ve since found a much bigger customer: schools.

The big picture: Companies like HopSkipDrive and Zum are getting much of their business from schools using their services to replace or supplement traditional school buses, especially for students with special needs or for trips outside of existing routes.

How it works: The drivers are contractors, but with a twist: They’re required to have child-care experience and pass rigorous background checks, including fingerprinting. In short: they’re babysitters with cars.

• While parents pay per ride or via monthly subscriptions, some companies sign longer contracts with schools and districts.
• Schools make up 80% of Zum’s business today, according to co-founder and CEO Ritu Narayan, and 70% of HopSkipDrive’s revenue, the company recently told TechCrunch.

What they’re saying: Garvey School District chief business officer Grace Garner told the Washington Post last year that her school district in Rosemead, California, saved more than half a million dollars in the first year of switching from buses to Zum, and cut down the commute of many special education students from 45 minutes to 15.

Between the lines: These companies' success underscores the undeniable gap in transportation suitable for kids, especially in suburbs and other less dense areas where public transit may not be accessible or safe.

Yes, but: As with other ride-hailing companies, questions remain about how environmentally friendly it is to have private cars shuttling kids to and from school rather than a large bus.

• Zum argues that it’s actually more sustainable because it offers a range of vehicle sizes including vans, replaces many instances where a parent would drive their child when school buses aren’t available or convenient, and that on average, each ride transports 2.8 kids.

The cul-de-sac has been a staple of urban development — and families' real estate wish lists — for the last 50 years. Now some cities are banning them from new developments.

Why it matters: Street-network sprawl determines a city's energy footprint.

• Researchers have found that city and suburban streets have become less connected in ways that favor car travel over more climate-friendly options.
• Grid-like streets are better for walking, cycling and public transportation, while cul-de-sacs, three-way-intersections and gated communities with "one-way-out" routes encourage vehicle use.

What's happening: City planners are encouraging denser street grids in new communities and redevelopments, or they could place a tax on three-way-intersections, or a "cul-de-tax," to change street design habits, write researchers Christopher Barrington-Leigh and Adam Millard-Ball in a recent study published in the Proceedings of the National Academy of Sciences.

• In Denmark, bicycle and pedestrian paths are being integrated into communities to connect otherwise disconnected streets.
• National planning guidance in the United Kingdom called for connected streets over dead-end designs.
• After a 2001 earthquake in Bhuj, India, planners tried to interconnect all cul-de-sacs to avoid dead-end streets being blocked by fallen rubble.

Tech sector growth isn't reaching beyond the usual tech hubs (Axios)

For growing numbers of struggling U.S. cities, the downturn has arrived (WSJ)

The great Wall Street Housing grab (NYT)

City Hall calls Google-backed LinkNYC consortium "delinquent" (Politico)

Parks are becoming part of a city's infrastructure to provide environmental, social and economic roles in addition to recreation.

The big picture: After decades of a lack of investment into parks, planners are reimagining how they can use spaces that were previously unattractive.

What's happening: Sharing the cost across utilities, health and housing programs, and economic development initiatives has made it easier to pay for parks with multiple funding sources.

The parks serve multiple purposes: playgrounds for recreation, linear parks for pedestrian and cycling routes, reservoirs for stormwater management, or central squares for pop-up fairs and gatherings.

• In Houston, voters approved a $100 million bond effort to transform 3,000 acres of land along nine bayous into a vast network of parks and trails.
• In Philadelphia, The Oval in front of the Philadelphia Museum of Art is a parking lot during the winter, but in warmer weather becomes a place for family activities. It's slated to be a permanent park.
• San Francisco installed a playground at the foot of City Hall to revive the neglected Civic Center Plaza.
• Providence, Rhode Island, turned a former brownfield site into a park with a bicycle pump track, trails and a parkour course. Its rain gardens reduce flooding.

What they're saying:

"Cities are doing this to remain economically competitive to attract families and young workers who eventually create their own families. But they're also making sure they're creating opportunities for existing residents who have weathered the storms of disinvestment."