While psychologists say that romantic relationships succeed due to compatibility and effort, it's hard to even start dating unless you live in the same place.

More than that, the data says that you probably need to be near the same age.

Which is why new research from the Martin Prosperity Institute at the University of Toronto is so exciting for singles trying to figure our their chances of finding someone.

Using data from the American Community Survey, the below maps show the cities where single women outnumber men — depending on the age group.

Within the 18 to 64 age range, the number of single women far exceeds the number of single men on the East Coast, while the trend reverses on the West Coast.

As noted by The Atlantic, there are:

• 230,000 more single women than men in New York

• 70,000 more single women in Philadelphia

• 65,000 more single women in Washington, D.C.

On the West Coast, there are:

• 50,000 more single men than women in San Diego

• 38,000 more single men in Seattle

• 20,00 more single men in San Francisco

But the story changes once we dive into age ranges.

In the 18 to 24 age group, single guys outnumber gals in almost every area.

It's the same for the 25 to 34 cohort.

Then, approaching middle age, the map goes pink.

Here's age 35 to 44.

And in the oldest age range, the pendulum swings all the way over to more single women.

What's going on here?

According to Martin Prosperity Institute demographer Karen King, the life courses of men and women provide a partial explanation.

While the present data can't say for certain, "the reasons could be of two things," she tells Business Insider. "In general there are more male babies than female, so there naturally are more males than females at younger ages. At older ages, the life expectancy of women is longer. Or it could simply be there were large influxes of single young men into cities."

