The population of Lawrence is more than just a number – it drives planning for the city’s future in many ways.

That’s why the sizable discrepancy between the city’s population estimates and those released in June by the U.S. Census Bureau needs to be resolved.

Lawrence city commissioners will discuss Tuesday whether to authorize an official challenge to the census figures. It seems that the city has nothing to lose by challenging the figures and everything to gain by getting a more accurate count – even if that number is lower than local residents would like it to be.

The Census Bureau has estimated Lawrence’s 2005 population as 81,816 people, almost 10 percent below the 89,643 estimate produced by the city’s planning department. Although city planners have gone to some lengths to validate their estimating methods, the Census Bureau has put the city’s population well below the local estimate for five years in a row. This year’s estimate, however, actually showed a decline in Lawrence’s population for the first time since at least 1900.

It’s clearly time to try to reconcile these figures.

Although city officials say they are convinced the census figures are wrong, local school district officials aren’t so sure. In fact, the experience of the Lawrence school district actually seems to confirm the census figures or some figure between the city and federal estimate.

School enrollments aren’t growing as fast as expected in booming sections of Lawrence, and districtwide enrollment is only holding steady because of increases at the Lawrence Virtual School. Officials speculate that high housing costs are discouraging families with children from moving to Lawrence, a factor that could skew the number of residents per household used in population estimates.

How university students are counted in Lawrence’s population figures often has fluctuated over the years. Another factor that might skew the figures is how the city estimates vacancy rates, especially in local apartment complexes.

The most important goal of challenging the census figures is not to figure out who’s right and who’s wrong; it’s to arrive at an accurate figure – that likely will be somewhere between the city and federal estimates – on which the city can base its planning for the future.

As the city considers major infrastructure improvements, such as a new $80 million sewer plant, officials need to have a reasonably good idea not only how many households it will be serving but how many households will be taxed to pay for the improvements.

The city needs to be realistic in its planning for the future, and that can only happen if it has reliable information on population figures and trends. No matter how painful it may be, the city needs to get an accurate reading on its population figures. An official challenge to the census figures would be a good first step in that process.