America could really use a civics lesson. And it's about to get one. The National Conference on Citizenship, a federally chartered nonprofit founded in 1946 to strengthen civic ties, will release the first Civic Health Index next week, tracking changes in the awareness and engagement of the citizenry over the past three decades. It presents a bleak picture--steep declines in most of the 40 measures that were analyzed, including how much people trust one another and major institutions, and their connections to their communities. The index offers a couple of bright spots: more citizens, especially young ones, vote now than in the disco era; and although volunteering has flattened out since spiking after 9/11, it's still on the rise among those between the ages of 16 and 24.

Still, we find it alarming that a country that is so prosperous, free and secure shows such serious signs of weakness in its civic infrastructure, especially at a time when it most needs that strength. The growing polarization of its politics has made compromise and unity on crucial matters far more difficult. Indeed, people's trust in others has declined even as their voting has climbed, suggesting that they're using the ballot to protect personal interests rather than out of a sense of shared responsibility. Americans are keenly aware of the fissures in society. Our surveys find that 96% believe the nation is deeply divided along economic lines, as many as say we are equally split along political ones.

So what's to be done? First, get a sharper picture of where we stand. The U.S. routinely collects minutely detailed information to gauge the vitality of its economy. This new index is the beginning of an effort to do the same for its civic life. With this data, we can begin to seriously debate and ultimately fashion robust policies to fix our communal machinery. Local groups can tap it to build awareness, and national service programs, such as AmeriCorps, can use it to hone recruiting. With just a little focus and effort, our civic health can change course.

By John Bridgeland, CEO of Civic Enterprises, and Robert Putnam, Malkin Professor of Public Policy at Harvard University. Both are on the advisory board of the National Conference on Citizenship.