Here’s the good news: It’s getting easier to rent in many parts of Greater Boston.

The bad news: That’s only true if your own income is increasing faster than rents.

And that’s indeed the case for many neighborhoods, where collective incomes have risen in past years faster than (also rising) rents. But in many other neighborhoods, the opposite has been true and rising rents, declining income levels — or both — have in some cases drastically increased what portion of their income renters are paying for housing.  

Fall River
Median annual household income: $22,500
Median monthly household rent: $630
Rent as portion of income: 34%

Dover
Median annual household income: $176,000
Median monthly household rent: $3,370
Rent as portion of income: 23%

Back Bay
Median annual household income: $125,400
Median monthly household rent: $2,400
Rent as portion of income: 23%

Mattapan
Median annual household income: $27,700
Median monthly household rent: $900
Rent as portion of income: 39%

Beacon Hill
Median annual household income: $99,400
Median monthly household rent: $2,250
Rent as portion of income: 27%

Roxbury
Median annual household income: $27,800
Median monthly household rent: $700
Rent as portion of income: 30%

South Boston
Median annual household income: $99,600
Median monthly household rent: $2,240
Rent as portion of income: 27%

Everett
Median annual household income: $46,200
Median monthly household rent: $1,424
Rent as portion of income: 37%

Davis Square
Median annual household income: $105,000
Median monthly household rent: $2,200
Rent as portion of income: 25%

Rent is just one component of the complex landscape of housing in our region — but an important one, especially in a city undergoing rapid demographic changes. 

And rent often provides a sharp view of the larger issue of income inequality. 

Around greater Boston, rents have been on the rise for years. Boston began 2016 with the fourth-highest rents in the United States. But that rise has been accompanied, in some parts of town, by overall rising wealth in the region — in some cases due to increasing wealth of residents; in others due to wealthier people moving into the region and less wealthy people moving out.   

As part of WGBH News's series on housing this week, we used data compiled by the United States census to take a closer look at not just what renters are paying where, but what portion of their income that cost represents — and how those figures have changed in recent years and over the last fifteen years.

One of our findings: Residents in some of the most expensive neighborhoods in Greater Boston are paying smaller shares of their income for rent than residents in many of Boston’s less-expensive neighborhoods. Conversely, renters in ostensibly cheaper locales are paying more, often much more, of their incomes just to meet those prices. 

Click here for an interactive version of this map.

In parts of Back Bay, Fenway, South End and downtown Boston — where the average one-bedroom apartment rents for $3,000 or more — residents are, on average, paying between a quarter and a third of their household income on rent.

In neighborhoods like Roxbury, Mattapan, parts of Dorchester and East Boston, and many areas surrounding downtown Boston, the story is often quite different. Many of those neighborhoods, the average renter is paying more than a third, or even more than half of their income on rent.

(One caveat to those already-alarming numbers: U.S. census data did not measure rent as a proportion of income above 50% — meaning some residents are undoubtedly paying much more even than that.)

It hasn't always been this way. WGBH compared data showing rent versus income in 2000 and 2014, the most recent year for which the data was available. The contrast is striking: Fifteen years ago, there were relatively few areas in and around Boston in which renters were paying (on average) more than about one-third of their income (light green below) on rent; many were paying less than one-quarter of their income on rent. 

By 2014, the number of renters paying between one-third and one-half, and more than one-half of their income on rent had increased drastically.  

Among the most consistently "rent-stressed" neighborhoods in Greater Boston now are the largely-minority neighborhoods south and southwest of downtown Boston, where residents are paying high portions of their incomes on rent in profound disproportion to other, more affluent areas.

It's a phenomenon Chris Norris, executive director of the Metropolitan Boston Housing Partnership, which assists low-income, homeless, and housing-threatened people with obtaining rental housing, primarily by issuing temporary vouchers to help cover rental costs.

The clients his organization serves — primarily working families making $20,000 or less annually — will find housing, if they do at all, "in one of three neighborhoods: Mattapan, Roxbury, and Dorchester." 

And even in those neighborhoods, Norris says, many are paying "Eighty, ninety, one-hundred percent" of their income on housing — levels clearly unsustainable without additional financial assistance, in this case housing vouchers.

Meanwhile, Norris says, costs are being driven ever upward by other renters, also burdened but with more means, competing for the same dwindling affordable rental stock. 

Without more rental housing and more affordable rental housing soon, Norris says, it's not just that lower-income families will pay ever-higher portions of their income on rent — they can't. 

"They'll leave — not just Boston," says Norris. "They'll leave the region altogether."

For the rest of the WGBH News Block By Block Housing Project, go to wgbhnews.org/blockbyblock.