At base, public spending at the municipal level is driven by two factors — people and property.

More (or fewer) people mean more (or fewer) voters, people to register cars, seek building permits, send children to school, drive the roads, visit the library, play in the park and so on across the various categories of public services.

More (or less) property means more (or less) stores to patrol, traffic to manage, fires to put out and so forth.

As towns grow and decline, therefore, the demand for municipal services grows and declines.

The problem for taxpayers and public officials lies in attempting to balance these changing forces of demand with the existing capital structure (roads, buildings, equipment) and labor force.

One problem arising from Maine’s legacy of more than 400 municipal entities is the wide swings in demand (or at least potential demand) that can arise from the different demographic patterns of individual municipalities.

It is interesting, for example, to look at the 2000 to 2010 population changes by municipality in two counties that are generally considered vastly different parts of Maine — Cumberland and Aroostook counties.

According to the Maine State Planning Office’s report from U.S. Census data, the population of Cumberland County between 2000 and 2010 increased by just over 16,000 people, an increase of approximately 6 percent over the decade.

But this increase was not spread uniformly across the county. Twenty-one of 26 municipalities (not counting Frye and Chebeague islands, which did not have separately enumerated populations in 2010) had positive population growth.

These ranged from highs of 20 percent in Sebago and 18 percent in Baldwin to less than 1 percent growth in Cumberland.

And four municipalities — Brunswick, Cape Elizabeth, Harpswell, Pownal and Yarmouth — experienced population declines.

Clearly, the demands for municipal services will vary widely from town to town because of these demographic differences.

These varying demands are not limited to southern Maine.

The population of Aroostook County fell by 1,974 people over the decade, a decline of nearly 3 percent. But even here, that pattern was not uniform.

In 38 municipalities and the unorganized territory of the county, population declined. The average decline across all these entities was 9.1 percent.

But at the same time, population grew in 31 municipalities. For them, the average change over the decade was an increase of 8 percent.

In short, the fiscal consequences of a sprawling population remain a significant issue even within an overall pattern of slowing, and even declining, overall growth.

The overall total demand for fire, police, roads, schools and other municipal services many not change, or may even decline, but if that demand keeps arising in new places, the demand in that place may exceed the current capacity to meet it.

More importantly, the cost of supporting the now unneeded capacity in other towns will become an even greater burden on the remaining taxpayers.

This trend highlights the even greater importance for Maine in an era of ever-increasing fiscal constraints of finding ways to share both the capacity to provide local services and the means to pay for it.

Charles Lawton is senior economist for Planning Decisions, a public policy research firm. He can be reached at:

clawton@maine.rr.com