The back-to-school season is upon us. Across the country, millions of children are preparing to hit the books. Many of those kids will be entering school for the first time, making this season a huge transition for them and their families. But for many families, starting school isn’t the only transition. Our analysis of Census data shows that 57% of households where the oldest child is between 5 and 9 years old said they moved sometime in the previous five years. Lots of factors go into the decision of whether to move and where, and for parents, this decision is largely driven by what matters most to their families: affordability, more space and of course good schools.

To figure out which school districts are the “most attractive” – in the sense that they attract families with school-age kids — we looked at the number of elementary school kids (by which we mean kids aged 5 to 9) and the number of preschoolers (kids aged 0 to 4) living in every school district in the U.S., according to the 2010 Census. The ratio of elementary school kids to preschoolers shows whether families move to or away from a district as kids approach school age. Since the Census is a snapshot in time, we can’t track individual families to see whether and when they actually moved to a different school district, but the ratio does reveal their overall movement patterns.

Here’s why: if families never moved, then the number of 5-to-9 year-olds would be very close to the number of 0-to-4 year-olds in an area, and the ratio would be very close to 1. (Nationally, the ratio is 1.01.) Children don’t just magically vanish after age 4; nor does the stork drop 5-year-olds from the sky. Therefore, a ratio below 1 indicates that more families are moving out of an area than are moving in as children reach school age. And vice-versa, a ratio above 1 indicates that more families are moving in than moving out. The higher the ratio, the more “attractive” the school district is, because it literally attracts more families with school-age kids.

Which districts attract families with school-age kids? Districts with higher ratios of school-age to pre-school-age kids tend to have, on average, much higher GreatSchools ratings, which we feature on Trulia Local schools maps. In addition to good schools, attractive school districts tend to have two other things going for them as well: (1) housing affordability – that is, lower price per square foot, and (2) lower population density, which means bigger houses and more parks, yards or other outdoor spaces. Neighboring districts matter as well: a not-too-bad school district could still lose lots of school-age kids and therefore have a ratio below 1 if it’s surrounded by great school districts. The ratio shows where parents move, and where future parents might move if they follow today’s parents’ footsteps.

Before we get into the rankings, here’s what we learned after looking at all of the data:

First: the school districts that attract parents with school-age kids include both pricey and relatively more affordable districts. The key difference between pricey districts that attract families – like Scarsdale or Beverly Hills – and more affordable and attractive districts – like Kinnelon Borough, in suburban New Jersey, or Walnut Valley, many miles east of Los Angeles – is the commute. To get an attractive school district AND a short commute to downtown, be prepared to pay. If you can’t afford top-dollar in your region, you might find yourself having to choose between a great school district for your kids or a manageable commute for yourself.

Second: don’t be tempted to guess which school districts families are drawn to. For example, you might think families want their school-age kids to be educated near great universities, but many great university towns have low ratios of school-age to pre-school-age kids, including Cambridge and Berkeley. Furthermore, places that might seem similar in many ways could actually be very different in their appeal to parents. For instance, the beach communities on the west side of Los Angeles include several that families move to, like Manhattan Beach and Palos Verdes, and some that families tend to move out of, like Redondo Beach and Santa Monica-Malibu. There’s no way to guess where parents move without looking at the data – which is why we did it.

So now, on to the data!

The Nation’s “Most Attractive” School Districts
The most attractive school district in the country for families with school-age kids is the Saratoga Union district, south of San Jose and next to Los Gatos. There are 2.38 elementary-school kids for every pre-school-age kid in that district. It’s an affluent and expensive area, with a median price per square foot of $607, but clearly families with school-age kids think that district is worth it.

Second is the Lovejoy Independent district, with a ratio of 2.15, in the northern Dallas suburbs just beyond Plano. Unlike Saratoga Union, Lovejoy is affordable by national standards and only a bit above the Dallas metro median of $87 price per foot. As we’ll see when we look more closely at individual metro areas, affordability often attracts families with school-age kids.

The third district with more than twice as many elementary-school-age kids versus pre-school-age kids is Cold Spring Harbor, on the North Shore of Long Island. School quality may not be the only factor that parents with school-age kids care about, but it sure helps: all of these most attractive districts have high GreatSchools ratings.

America’s Most Attractive School Districts

School District

Ratio

Price per SQFT

Metro area

Saratoga Union Elementary School District, CA

2.38

$603

SF Bay Area

Lovejoy Independent School District, TX

2.15

$92

Dallas

Cold Spring Harbor Central School District, NY

2.09

$322

New York

Glencoe School District 35, IL

1.93

$277

Chicago

San Marino Unified School District, CA

1.92

$536

Los Angeles

Weston School District, CT

1.92

$258

New York

Hillsborough City Elementary School District, CA

1.90

$649

SF Bay Area

Colts Neck Township School District, NJ

1.87

$252

New York

Madison School District, CT

1.87

$204

New Haven

Warren Township School District, NJ

1.86

$260

New York

Note: The ratio is the number of 5-to-9 year-olds divided by the number of 0-to-4 year-olds living in the school district. Ranking is among districts in the largest 100 U.S. metro areas with at least 1,000 0-to-9 year-olds. Click here to download the full list of school rankings by ratio and the full list by state.

At the other extreme, kids disappear from Hoboken, Alexandria VA, Somerville MA and other districts on the bottom-ten list by the time they reach school age. Hoboken has only 39 elementary-school-age kids per 100 pre-school-age kids. According to one Hoboken resident, whom I won’t name but who happens to be my mother, a well-known local saying is “Hoboken plus five years equals Montclair” (the Montclair school district, about 15 miles west of Hoboken, has a ratio of 1.30). Many of the places that families leave are also expensive: Hoboken and Cambridge real estate is more than $400 per square foot. And at those prices, schools would need to be top-ranked in order to retain or attract families. If you live there now or are thinking about moving there, you might find yourself looking to move out if and when you have kids who are ready to start school.

America’s Least Attractive School Districts

School District

Ratio

Price per SQFT

Metro area

Hoboken City School District, NJ

0.39

$478

New York

Orchard Elementary School District, CA

0.51

$299

SF Bay Area

Edgewater Borough School District, NJ

0.59

$396

New York

Alexandria City Public Schools, VA

0.64

$307

Washington, DC

Palisades Park Borough School District, NJ

0.64

$226

New York

Watertown School District, MA

0.67

$283

Boston

Somerville School District, MA

0.67

$333

Boston

Sunnyvale Elementary School District, CA

0.67

$395

SF Bay Area

Maplewood-Richmond Heights School District, MO

0.68

$118

Saint Louis

Cambridge School District, MA

0.68

$454

Boston

Note: The ratio is the number of 5-to-9 year-olds divided by the number of 0-to-4 year-olds living in the school district. Ranking is among districts in the largest 100 U.S. metro areas with at least 1,000 0-to-9 year-olds. Click here to download the full list of school rankings by ratio and the full list by state.

The largest metro areas in the U.S. dominate both the top and bottom lists. Big metro areas typically have more school districts and therefore have a greater variety of schools to choose from and move among.

Notice which districts are missing from the least-attractive list? Big-city districts. While the ratios are less than one for New York City (.91), Los Angeles Unified (.93) and Chicago (.89), they lose fewer school-age kids than Hoboken, Sunnyvale, Alexandria and Cambridge. Why? One reason is that big-city districts often have big variations of school quality within them, including selective or magnet schools with strong reputations, which keep some families within the district. Another is that plenty of rich families in big cities send their kids to private school and don’t need to move for better public schools. Finally, big cities have a disproportionate share of poorer families who rely on public transportation and other urban public services and therefore might not move to the suburbs that offer worse public services.

Metro by Metro: Most Attractive Districts Cost Top Dollar
— Or A Long Commute

The national top-ten list may inspire bragging rights – go Saratoga! – but most families probably don’t move to a different part of the country in order to live in a particular school district. Rather, families look within a region or metro area to decide where to move for the sake of the kids. Let’s take a quick tour across the most attractive districts in the greater New York, Los Angeles, San Francisco and Boston areas. Some of the most attractive districts are top-dollar neighborhoods, but there are more affordable districts that also draw in families with school-age kids.

First, New York. The most attractive school districts hit all the suburban regions that surround New York City. Cold Spring Harbor is on Long Island; Weston in Connecticut; Scarsdale in Westchester county; and several in New Jersey. The home-price variation among these top districts is wide, with the per-foot prices in Kinnelon Borough well below others on the list.

New York’s Most Attractive School Districts

School District

Ratio

Price per SQFT

County

Cold Spring Harbor Central School District

2.09

$322

Nassau NY

Weston School District

1.92

$258

Fairfield CT

Colts Neck Township School District

1.87

$252

Monmouth NJ

Warren Township School District

1.86

$260

Somerset NJ

Franklin Lakes Borough School District

1.83

$320

Bergen NJ

Tenafly Borough School District

1.80

$325

Bergen NJ

Scarsdale Union Free School District

1.80

$339

Westchester NY

Upper Saddle River Borough School District

1.79

$316

Bergen NJ

Kinnelon Borough School District

1.79

$194

Morris NJ

Chester Township School District

1.78

$214

Morris NJ

Note: The ratio is the number of 5-to-9 year-olds divided by the number of 0-to-4 year-olds living in the school district. Ranking is among districts with at least 1,000 0-to-9 year-olds. Click here to download the full list of school rankings by ratio and the full list by state.

In Los Angeles, the most attractive school districts are not the famous ones. Beverly Hills ranks tenth, but the other top districts are hardly household names. San Marino is next to Pasadena; La Cañada is north of downtown Los Angeles, beyond Glendale. Several beach communities make the list, including Palos Verdes, Laguna Beach (Orange County) and Manhattan Beach. But an ocean view doesn’t necessarily attract families with school-age kids: Redondo Beach, just a few miles south of Manhattan Beach, has the lowest ratio of all districts in the Los Angeles area, at .84. Finally, we call out ActonAgua Dulce and Walnut Valley, which have a stronger pull on school-age kids than Laguna Beach, Manhattan Beach and Beverly Hills – at a fraction of the price. What’s the catch? Acton – Agua Dulce is 50 miles north of downtown Los Angeles, near Palmdale; Walnut Valley is 25 miles east of downtown, near Pomona. That could mean a long way to work – or to the beach.

Los Angeles’s Most Attractive School Districts

School District

Ratio

Price per SQFT

County

San Marino Unified School District

1.92

$536

Los Angeles CA

La Cañada Unified School District

1.73

$457

Los Angeles CA

Palos Verdes Peninsula Unified School District

1.72

$456

Los Angeles CA

Las Virgenes Unified School District

1.47

$308

Los Angeles CA

Walnut Valley Unified School District

1.38

$267

Los Angeles CA

Acton-Agua Dulce Unified School District

1.35

$147

Los Angeles CA

Laguna Beach Unified School District

1.33

$651

Orange CA

Arcadia Unified School District

1.32

$361

Los Angeles CA

Manhattan Beach Unified School District

1.31

$670

Los Angeles CA

Beverly Hills Unified School District

1.28

$616

Los Angeles CA

Note: The ratio is the number of 5-to-9 year-olds divided by the number of 0-to-4 year-olds living in the school district. Ranking is among districts with at least 1,000 0-to-9 year-olds. Click here to download the full list of school rankings by ratio and the full list by state.

On to the San Francisco Bay Area. As with New York and Los Angeles, the top districts cover all parts of the Bay Area. Saratoga and Los Gatos are to the south, beyond San Jose; Moraga, Orinda and Lafayette are in the outer East Bay, beyond Oakland; and Reed Union serves the upscale Marin County communities of Belvedere and Tiburon. Surprisingly, there’s not a lot of Silicon Valley on this list. Cupertino – home of Apple – is, but Sunnyvale and Mountain View Whisman districts – near the heart of Silicon Valley – have some of the lowest ratios in the Bay Area. And Hillsborough may be on the Peninsula, but is closer to San Francisco than to Silicon Valley. By national standards, no place in the Bay Area is affordable, but the outer East Bay school districts –Moraga, Orinda and Lafayette — will cost you a lot less than those closer to San Francisco or San Jose.

San Francisco Bay Area’s Most Attractive School Districts

School District

Ratio

Price per SQFT

County

Saratoga Union Elementary School District

2.38

$603

Santa Clara CA

Hillsborough City Elementary School District

1.90

$649

San Mateo CA

Piedmont City Unified School District

1.69

$552

Alameda CA

Moraga Elementary School District, California

1.69

$368

Contra Costa CA

Orinda Union Elementary School District

1.66

$415

Contra Costa CA

Los Gatos Union Elementary School District

1.52

$547

Santa Clara CA

Lafayette Elementary School District

1.45

$397

Contra Costa CA

Cupertino Union Elementary School District

1.44

$538

Santa Clara CA

Los Altos Elementary School District

1.44

$687

Santa Clara CA

Reed Union Elementary School District

1.36

$696

Marin CA

Note: The ratio is the number of 5-to-9 year-olds divided by the number of 0-to-4 year-olds living in the school district. Ranking is among districts with at least 1,000 0-to-9 year-olds. Click here to download the full list of school rankings by ratio and the full list by state.

Finally, Boston. College students may move to Cambridge for Harvard and MIT, but elementary school students are going in the opposite direction. Westford has the highest ratio of school-age kids to pre-school age kids in the Boston area, followed by Duxbury and Westwood. Pricey Weston and Lexington are also among the most attractive Boston area school districts. The most affordable of these districts are Pentucket, north of Boston, and Groton-Dunstable, to the west, along with Westford – but those three districts are a much longer commute to downtown Boston than Weston and Lexington are.

Boston’s Most Attractive School Districts

School District

Ratio

Price per SQFT

County

Westford School District

1.74

$197

Middlesex MA

Duxbury School District

1.72

$231

Plymouth MA

Westwood School District

1.70

$289

Norfolk MA

Weston School District

1.70

$350

Middlesex MA

Medfield School District

1.68

$242

Norfolk MA

Pentucket School District

1.68

$180

Essex MA

Sudbury School District

1.68

$242

Middlesex MA

Groton-Dunstable School District

1.66

$177

Middlesex MA

Lynnfield School District

1.64

$239

Essex MA

Lexington School District

1.63

$321

Middlesex MA

Note: The ratio is the number of 5-to-9 year-olds divided by the number of 0-to-4 year-olds living in the school district. Ranking is among districts with at least 1,000 0-to-9 year-olds. Click here to download the full list of school rankings by ratio and the full list by state.

All in all, these school-district ratios are a great start for thinking about where to move as your kids reach school age – but they’re only a start. There are lots of reasons why families might flock to or flee from a school district: it might be the schools themselves, or it could also be affordability, the types of houses available or other reasons. Even if it is the schools, many districts – especially big-city districts — have multiple elementary schools, and some schools are inevitably better than others. To see what this means for you, start your research on Trulia, where you can find homes for sale and rentals while also checking out school district boundaries and detailed school info including GreatSchools ratings (now available on our iPad app), as well as detailed heatmaps on crime rates and commute times.

NOTE: Click here to download the full list of school rankings by ratio and the full list by state.