Take a map of Northern New England and stick a pin right in the heart of Boston, say the financial district. Now, tie a thread to it.

It’s uncanny, but the further you stretch that string the poorer people get.

In the counties just north of Boston, per capita family income is well over $60,000. Stretch it into New Hampshire and it drops to about $55,000. Stretch it just across the border into southern Maine and it’s about $45,000.

Stretch it all the way to Coos County in northern New Hampshire, and per capita family income drops to about $33,000. Swing over to Washington County in Maine, and it drops to about $26,000, the lowest in New England.

It’s not absolutely true; there are pockets of poverty and wealth everywhere.

But, generally, the further south a person lives in Maine, the higher their family income. Ditto for New Hampshire.

The further north, the poorer.

All of the wealthiest communities in both states are located in their southern reaches. The poorest are in the north.

Why the differences?

Gov. Paul LePage put forth a good theory in his radio address Saturday. New Hampshire is a “more welcoming place for commerce,” he said.

And he may be right. But that doesn’t explain why you can jump right across the border from New Hampshire into Massachusetts and incomes soar even further.

Taxes are high and the regulatory burden in Massachusetts is probably even heavier than Maine, and yet it is also one of the wealthiest states in the U.S.

Boston is an economic powerhouse because it has a highly educated workforce, research universities, a harbor and a major airport.

Yet it’s funny that politicians in Maine never say we need to be more like Massachusetts.

When you look at a map, you will see one other significant difference between New Hampshire and Maine.

New Hampshire has two excellent interstate highways that run right into the heart of the Boston metro area. Those two interstates also link Boston to the two circumferential highways surrounding the city, 495 and 95.

New Hampshire also has an excellent east-west interstate, 101 and 89.

And you know what? No tolls on those roads. Talk about being welcoming to business! Try not charging to get in and out.

The place New Hampshire does have a toll is for people trying to get into Maine.

So, let’s say you are in Boston and you want to build a factory that ships products by truck. Where would you locate?

In New Hampshire, where you could use interstates 3 and 95 to access 495, all for free?

Or Maine, where a six-axle tractor trailer would cost you $9 at the York Plaza and then another $6 at Hampton? That’s a tax of $14 per truckload of goods.

Or let’s say you work in the Boston suburbs and harbor a desire for rural living.

A commute into New Hampshire would cost you nothing, while your drive to southern Maine would cost you $3.40 each way, and that’s with a Transpass.

Over the course of a year, that would be a $1,700 “commuter” tax for living in Maine.

Is there any wonder, then, why commerce is booming along those interstate corridors into New Hampshire?

Comparisons between Maine and New Hampshire are, of course, endlessly interesting — especially to politicians in Maine.

But they should compare all factors.

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The opinions expressed in this column reflect the views of the ownership and editorial board.