In the District of Columbia, the poor are more likely to move out of the city than the rich, according to a recent report by D.C.’s Office of the Chief Financial Officer (CFO).

Looking at the district’s tax rolls from 2004 to 2012, CFO analysts found that the city sees a lot of turnover, regardless of income. Only 22 percent of people who first filed in 2004 were still on the tax rolls in 2012. However, transience was less pronounced among high-income residents, defined as the top 20 percent of tax filers -- people who earned more than $96,566. (The tax filers could singles, couples or families.) About 41 percent of tax filers in the top 20 percent remained on the tax rolls in 2012.

The report also looked at tax filers in the bottom 20 percent -- households that earned less than $14,841. They were more transient than the high-income filers. Only a quarter remained on the tax rolls by 2012.

While the data may lead people to conclude that rising housing costs and gentrification are to blame for the high transience of low-income residents, that causal relationship isn't proven by the CFO report. "We didn’t talk to anyone about why they left," said Yesim Taylor, D.C.'s director of legislative and fiscal analysis. "There could be myriad reasons."

One finding in the report is that getting married and having children may increase someone's likelihood of staying in the city. The tax data show higher rates of staying in the city when filers changed their status (usually because of marriage) or added dependants. Taylor's interpretation was that both marriage and children caused residents to lay down roots that made it harder to leave later on.

City officials may want to think about how to retain more of those tax filers, both wealthy and poor, through improvements in public education and affordable housing, said Derek Hyra, director of the Metropolitan Policy Center at American University. He also cautioned that the report focuses on the retention of a relatively small number of D.C. residents, about 13 percent of all tax filers in 2004.

"It’s the pattern of newcomers [from that year]," he said. "You have to be careful about making generalizations to the entire city."

The report comes during the first 100 days of a new administration under Mayor Muriel Bowser, who has made affordable housing an early priority. She has already halted development at three locations to make sure they meet new, higher affordable housing requirements under a law passed last year. To head her department of human services, Bowser appointed a national leader on homelessness, Laura Zeilinger, who previously served as the executive director of the U.S. Interagency Council on Homelessness.*

By some measures, Washington, D.C., is now the most expensive major city in the country. One recent study found it would take an annual income of $108,092 to live comfortably in the district. Between 2000 and 2010, the number of low-cost apartments dwindled from 70,600 to 34,500, according to a 2012 report by the D.C. Fiscal Policy Institute, a local think tank. At the same time, the number of high-cost apartments more than tripled. While the average income has grown during that time, it hasn't kept up with rising housing costs.

The district is one of the fastest-gentrifying cities in the country, which has raised concerns that as neighborhoods become wealthier, their low-income residents can't afford increases in rent and property taxes or are getting forced out through more explicit means, such as evictions. Some research has raised doubts about how often that type of direct displacement actually occurs.

The March issue of Governing focuses on gentrification, including a feature about rapid change in Columbia Heights, a neighborhood in northwest D.C. Public officials, housing advocates and academics dispute what exactly constitutes gentrification and how it affects residents.

The CFO report won’t end that debate. “All we can say is that low-income people are more likely to leave,” Hyra said. “This data tells you trends. It’s suggestive, but it’s not proof.”

*CORRECTION: A previous verson of this story incorrectly listed Laura Zeilinger's new position. She has been appointed the director of human services.