When Terry Strine leaves his house on the Chester County side of Chadds Ford, Pennsylvania, for his morning commute, a line of traffic stretches down Pa. 41 into New Castle County. Strine, who founded Leadership Delaware, a mentorship program for promising young Delawareans, sees the traffic as a daily reminder of a trend changing the region.
"It was true 15 years ago. It's more true today," Strine said. "People are leaving New Castle County to move to Chester County."
Data largely backs up what Strine sees play out on Route 41 every morning. The U.S. Census Bureau's American Community Survey found that in 2013 more than 14,600 people commuted daily from Chester County to New Castle County. A little under half that amount commuted in the opposite direction.
In addition, IRS data from the same year shows that about 1,400 people moved to Chester County from New Castle County. About 1,150 moved the opposite way - a net loss of 250 people for Delaware.
The counties' shared border explains part of the heavy crossover. (Indeed, all of the surrounding counties send thousands of workers into downtown Wilmington and the corporate campuses that surround the city.) But the sheer number of people coming in from Chester County, and the loss of residents, has left some wondering if Delaware has become a less appealing place to live and work.
"It's really all about the schools," said John Stapleford, a conservative economist and founder of Econ First LLC, a business consulting firm. "When the kids turn school age, the parents bail out."
Stapleford traces migration out of New Castle to Chester County back to the 1978 school desegregation order, which imposed forced busing on school districts in northern Delaware. The order sparked a wave of "white flight" out of the county, leaving those left behind to pay for private school or send their kids to increasingly low-income public schools.
"This has been going on a for a while," said Daniel Blevins, principal planner at the Wilmington Area Planning Council. "It goes back to the '80s, when school desegregation settled in. That started the whole process of people moving into Chester County."
New Castle County schools continue to underperform compared to surrounding districts, which has left some middle- and upper-middle-class parents with a hard economic choice: budget for private schooling or move to another school district.
"While our leaders can claim that New Castle Schools are just fine, and they may be right, only perception counts," said Strine, who moved to Pennsylvania years after his children were grown but has nonetheless watched the trend up close. He added that southern Chester County public schools have a good reputation across the region.
"Every ZIP code in northwest New Castle County has seen a decrease in households with school-age children," Stapleford said, referencing his own research.
The migration has an impact beyond lost population. There's also the issue of lost wealth.
Travis H. Brown, economist and author of "How Money Walks," has created a cottage industry around showing people how money moves between counties and states. Using IRS data, Brown created an interactive online map that shows how much money an area loses or gains due to migration.
New Castle County lost $665.90 million to Chester County between 1992 and 2015, according to IRS data presented in the map. That's more than three times the amount it lost to Sussex County, the second biggest draw from New Castle.
Stapleford pointed out that per capita income in New Castle and Chester was roughly equal in 1970. Today Chester County boasts a 42 percent higher per capita income.
It's not clear, though, whether the divide is a sign of New Castle's decline or simply Chester County's own skyrocketing real estate values. On the other side of the state line, the relationship is seen as somewhat unavoidable, given the close proximity of the two counties.
"I think it's been a steady relationship," said David Ward, assistant director of the Chester County Planning Commission. "People like to reside in Chester County, even if they are employed in Delaware."
Delaware also isn't the only area feeding into Chester County's housing boom. Delaware and Montgomery counties in Pennsylvania each lost over 3,000 residents to Chester County, compared to 1,400 from New Castle.
Ward said that Chester County lacks major employers, so naturally residents are going to commute to other counties, especially skilled job hubs like Wilmington. In addition, while he recognizes the school issue, he noted that Chester County also has an inherent appeal for families looking to settle down, such as its charming rural qualities and burgeoning main streets in Kennett Square and West Chester.
Strine, for his part, made the move for similar reasons.
"The factor for us was the home, the property, etc. That's what motivated us," he said.