In the charitable ritual that has evolved, two sides expend energy, but only the sponsors’ efforts directly aid the poor. The others’ is pure sweat equity that goes nowhere but down the necks of the participants. Consider, too, the public resources expended: the rescue squads and medics along the way, the police sealing off urban arteries, the snarling of traffic. We tie our cities in knots. Enduring such inconvenience is what each of us gives to the cause.

I do not question the sincerity of the participants, but in these mass mobilizations I see many lost opportunity costs. I recognize the value of exercise and companionship, but question why society values these schemes.

The easy explanation, of course, is that there would be no giving — or not nearly so much — without the walks. Fund-raisers recognize that the nobility of giving is often stimulated by activities that conjoin the selfless with self-interest. For giving, we often offer value received. Raffles and auctions and naming rights are among the inducements used to win support. But that’s not what’s going on here.

Those who oversee such fund-raising spectacles argue that there is more to these events than meets the eyes — mine included. These walks and runs are incubators for future volunteers and donors. They constitute a public proclamation that others matter. They make the invisible visible. More to the point, it is easier to get relatives, friends and colleagues to open their pocketbooks than it is to win over the largess of strangers.

That is the genius of such events. Where abstract appeals on behalf of the faceless needy may fall on deaf ears, appeals from family and neighbors do not. Ultimately, it is not the mass of walkers that moves us to give, but the knowledge that a familiar face — a nephew or friend — is among them. It personalizes the issue, quite literally turning the abstract into the concrete, converting perspiration into philanthropy. There is an exquisite — albeit attenuated — logic to it all.