Lake County again posted the biggest drop in population in the state, falling to an estimated 487,865 residents last year, down from 490,574 in 2014, as residents left the county for greater economic opportunity.
Northwest Indiana's largest county, and second largest in the state, saw its population decline by 0.5 percent last year, according to the latest U.S. Census data. Its population has fallen by 1.6 percent since 2010.
Lake County's population, which exceeded half a million as recently as the early 1980s, has now fallen seven straight years.
Porter County's population has grown by 2 percent since the last census in 2010, while LaPorte's has fallen by 0.5 percent over that time period.
Internal Revenue Service figures from 2013 to 2014, the most recent data available, show more people are leaving Lake County than are moving in, and the majority are headed out of state, often to cities such as Phoenix, Las Vegas, Houston, Atlanta, Dallas, Orlando, Florida, and Austin, Texas.
LaPorte County saw its population fall to 110,884 residents in 2015, a 0.7 percent decline from 111,695 residents in 2014. Porter County grew by 0.2 percent to 167,688 last year, up from 167,308 the previous year.
The Chicago metropolitan area, of which Northwest Indiana is a part, saw the biggest decline of any metro area in the country in 2015, and Cook County's population shrunk for the first time since 2007.
Northwest Indiana's demographic fortunes are tied to the greater metro area, but the Region also has its own set of challenges.
"Simply put, we’re losing population because we’re not doing enough across the board to make our region a more desirable place for the next generation," said Indiana University Northwest assistant professor of economics Micah Pollak.
The biggest issue in an area where the economy has been sluggish is jobs.
"While the unemployment rate went down significantly in 2015, there was no job growth in Northwest Indiana, compared to a 1.8 percent growth in jobs in Indiana and 2.1 percent nationwide," Pollak said.
"At the same time, average wages have been declining in the Region while going up nationally and in the Chicago area," he said. "Without a strong economy and available jobs, it becomes very hard to convince families this is a desirable place to live."
But there's also the matter of quality of life, and having enough amenities to attract and retain young families, Pollak said.
"For a modern urban area to successfully attract a younger generation it needs to offer high-end shopping, restaurants, coffee shops, microbreweries, bicycle-friendly roads and trails, walking-friendly green spaces and parks and convenient public transportation," Pollak said.
"Developments like Shops on Main in Schererville and the entrepreneurship we see in the Griffith downtown are two positive examples," he said.
The economist cited the proposed South Shore Line extension as a positive development, because it means improved public transportation and better access to amenities in Chicago. The Region needs to encourage additional development and growth along those lines to prosper, Pollak said.
Quality of education also is one of the main things families look at when deciding where to live, he said.
"While we have many excellent schools and educational facilities, most have faced budget challenges at a time when the state is posting budget surpluses and record levels of reserves," he said.
In order to effectively grow its population the region needs to develop into a desirable place to raise children as well as provide modern amenities and services to attract and retain a younger generation, Pollak said.
Congressman Pete Visclosky, D-Merrillville, has long been pointing to Lake County's declining population as a reason for making "transformative investment," similar to how industrial titans built steel mills and oil refineries in the early 20th century. Visclosky for instance has worked to expand the South Shore Line to better position the Region as a bedroom community for Chicago, which has an economy that's bigger than Sweden's.
"The 2015 census estimates are a reminder that we must move with all deliberate speed to implement transformational investments in our region," Visclosky said. "We are not without resources and assets in Northwest Indiana. We must work to develop them fully in order to retain current residents and attract new individuals and businesses to our area."