The election is two weeks from today, and at my house, you don't really need a calendar to know that. The imminence of the election is obvious on the television, in the mailbox and even on our home answering machine.

Yesterday, my wife retrieved a message from the answering machine from some unnamed caller who addressed her as "Virginia" — her legal name but one that no one ever calls her. He used the name twice in his message, each time with a brief, awkward pause before enunciating her name. He wanted to tell her about "cap-and-trade," a failed proposal to reduce carbon emissions by creating a global market in emissions permits. The proposal would have cost thousands of jobs, the caller said, and Sen. Kay Hagan voted for it, as if she hated jobs and wanted thousands of North Carolina residents to be unemployed. Never once did he tell "Virginia" to vote against Hagan two weeks from today. Instead, he urged her to call the senator and complain about her vote for cap-and-trade.

The caller's script was eerily similar to fliers we had received in the mail. The slick, brightly colored, over-sized fliers accused Hagan of the cap-and-trade sin and urged us to call her office and complain. Two of these fliers — similar in design and printing but different — arrived in one day.

Yesterday's caller identified himself as calling from "Crossroads GPS," a group founded by Karl Rove, George W. Bush's campaign guru. I believe the fliers also came from Rove's group, but I've thrown them away and can't remember for sure.

These intrusions into our home privacy are evidence of the tens of billions of dollars that are being spent on the North Carolina U.S. Senate campaign this year by both Democratic and Republican supporters. Some of the money is being spent in the traditional way by the candidates' campaigns and some by their respective parties, but even more is being spent by "independent" groups, which have been legalized by legislation and court decisions.

All this makes me wonder about the "opportunity cost" — a term from my two semesters of economics. Opportunity cost is simply what one forgoes in spending money. For example, if you buy a couple of $100 tickets to a rock concert, you forgo the opportunity to spend that money on other things, such as groceries or a car repair or a chair for the living room.

What is the opportunity cost of the billions of dollars being spent on this year's election campaigns? Imagine what a few hundred billion dollars could do to control Ebola in West Africa or to invest in child care for the poor or to improve America's passenger rail system or to reform public education.

One simple lesson I learned from economics (and from life) is that everything has its cost. Are we spending wisely?