Demographics beat: New app tells you who's living near where you are

The normally stuffy U.S. Census Bureau has come up with something surprisingly youthful: a new product that feels like a slick mobile app for the smartphone-toting dating set.

Dwellr, a free download, is aimed at those searching for a home and wanting to know about key demographics — wealth, education and so on — for the part of town they're in.

But it also provides a lesson on the power of an amenity to alter property values and therefore lots of other things.

And when you use it, it feels like it's aimed at young adults in quest of mates, with its stress on age and marital availability.

As you swing around the northern rim of Lake Calhoun, for example, it tells you you're now at the southern edge of a posh part of town: median home values of $565,000, with relatively few young adults (19 percent, ages 20 to 34), and very few taking the bus (4 percent).

The moment you reach the east edge of the lake, where apartment buildings proliferate, the never-married quotient leaps from 32 to 66 percent and the young-adult share soars even more, up to just over half. Education's still high and almost everyone's still white, but incomes have shrunk.

Moving farther east, past Hennepin Avenue, transit use rises to 12 percent, three times higher than where you started. College degrees slump, from 48 percent to 37 percent. And so on.

• Keep a careful eye out (there's a tiny map) for the size and boundaries of the neighborhood you are being told you are in. Sometimes the numbers you see are being influenced by people far from where you are.

• Beware of margins of error. The device purports to tell you how much, say, media/arts types make. But the number seesaws; you are looking only at survey results, with margins of error that can grow huge if the group is tiny. Yet there's no message to warn you of that as the numbers pop up.

Still, it's pretty cool, even for people who think they know the area, and would be useful for raw newcomers or out of curiosity during a trip somewhere.