New numbers released by the U.S. Census Bureau Monday showed that Massachusetts' population increased over the past 10 years; a rise of 5% to roughly 6.8 million people due to immigration from abroad. Yet the state also appeared among the top five of states that people are leaving, a trend reflective of the northeast.

Paul Watanabe is a political science professor at UMass Boston. He spoke with WGBH News' All Things Considered anchor Arun Rath about these slightly confusing numbers. This transcript has been edited for clarity.

Arun Rath: So let's start with this 5-percent gain that we've seen since 2009. Give us a quick demographic breakdown. Do we know who is moving to Massachusetts and why?

Paul Watanabe: Well, what we're seeing is the net effect of two phenomenons. On the one hand, we're seeing a stabilization of the native and largely nonwhite population, a very moderate growth within that population. But that has been more than offset by another thing, and that is the growth through immigration or international migration as opposed to the hemorrhaging that's taking place because of domestic migration. So the net effect of this is the state is growing. It's one of the few states in the northeast that is growing, but it's principally due to one thing, and that is because of our attracting immigrants from other countries to come to our state. And it's attractive for a number of reasons. It's been a long area in which we've had different immigrants over the years be attracted to Massachusetts because of its cultural and social and political and more recently, its economic attractability. And it's also been a place in which we've also been considered to be a welcoming place for immigrants, a place in which we reached out for them, and that's had an impact as well. It's a place where many immigrants come to Massachusetts, perhaps not as their initial site of relocation, but eventually many of them end up here, joining other communities.

Rath: So let's talk about the population that is leaving. We rank fifth in the country in terms of people moving elsewhere. So on the other side, who's leaving, why are they leaving, and where are they going?

Watanabe: Well, it's largely the native population. And many people are leaving for some of the reasons which makes, on the other hand, Massachusetts somewhat complex in terms of its attractiveness to some and its inability to retain a lot of its citizens. And that's principally because of something that most people are aware of. While we have some great economic successes, it translates into some very high housing costs. And those housing costs have shut a number of people out, particularly in terms of an elderly population which is seeking opportunities in other areas and causing flight towards other places, like the south. So again, it's a largely white population that's seeking that kind of movement. And that's why we're seeing in terms of the national data, places like Florida and Texas, the population is growing there, as opposed to the northeast, where generally it is declining.

Rath: I'm curious, as someone who studies the census and demographics, is this kind of massive outflow of population and inflow at the same time, is it as peculiar as it seems? For an expert like you, what do these numbers tell you?

Watanabe: Well, we are seeing a fairly unprecedented in the last few decades growth in the immigrant population coming into the United States. And that number has been really the engine that's driven any growth that we've had, particularly in this region of the country. We saw a very large number of immigrants coming to the United States at the turn of the 19th into the 20th century. Well, a hundred years later, we're seeing this phenomenon taking place.

But while at that time the immigrants were largely European, thus of white origins, now the immigrants are largely of nonwhite origins. So it's meant that not only have the numbers increased, but the diversity has increased substantially. So much so that in Massachusetts, and in the nation as a whole, we are quickly in a few decades going to move to a status in which the country is likely to have a majority nonwhite population.

Rath: Finally, I want to ask you, these numbers are out ahead of this year's official U.S. census. What are you most excited to dig into in terms of the data that we'll get from that, for Massachusetts?

Watanabe: The census, as we know, is a headcount. It's an attempt to capture all of the people living in Massachusetts and around the country. And that headcount is going to be the final determinant of things like political representation, the extent to which Massachusetts and other areas get their share of governmental services and funding. And therefore, it's critical that the census itself be the really important count that takes place. And there are a number of challenges facing the census in 2020. It's incumbent upon the citizens and residents of Massachusetts and those who care about maintaining this social, cultural, economic and political representation and strength that immigrants and others bring to Massachusetts, that they indeed respond to the census, and that we make a total effort to see that everyone is counted.