It’s important to remember the past and to learn from it, but you’ll never move ahead if you spend all your time looking backward. So why do so many presidential candidates spend so much time peering over their shoulders?

“The first time I ever came out to Iowa was with Senator Culver on his first campaign in ’74. And one thing seems different now. You ride across this magnificent state and you see so much open land -- and so few farmers,” Sen. Joe Biden said during a Democratic debate on Dec. 13. And, he wondered, “How do you preserve family farmers? [There are] only 550,000 of them left. And if you continue the system the way it is, it’s breaking the system. It’s going to just flat break the system.”

But asking how many farmers there are in Iowa, or in the entire country, entirely misses the point. The correct question is: “Are we producing enough food?” Our farms produce more food than ever. We feed the world. Meanwhile, the USDA says American families spend less than 10 percent of their disposable income on food, leaving us more money for other things. If fewer farmers are growing more food, it’s difficult to understand why that’s a bad thing.

Former Sen. John Edwards, who’s positioning himself as the enemy of American corporations, is also stuck in the past. He claims that, because of trade with China, we’ve “lost millions of jobs.”

Wrong. The United States has added jobs in each of the last 51 straight months. Wages are increasing, too, and unemployment rates remain extremely low. If George Bush has presided over the “worst economy since Herbert Hoover,” as John Kerry claimed in 2004, it’s difficult to imagine what a good economy would look like.

Of course, in any active economy, people do lose their jobs. And Edwards has met at least one of those people. “Right here in Iowa, the Maytag plant in Newton closed. A guy named Doug Bishop, who I got to know very well, had worked in that plant and his family had worked in that plant literally for generations. And his job is now gone. The same thing, by the way, happened in the plant that my father worked in when I was growing up,” Edwards declared.

It is a shame when anyone loses a job. But it’s critical to remember that, in order for an economy to grow, there simply must be some disruption. When globalization works, some people are going to lose their jobs, but more people are going to gain jobs. That’s exactly what’s happened in the U.S. economy in recent years.

Edwards mentioned textile plants, so let’s go even further back, before his father’s day, to the early 1900s. Back then, South Carolina’s economy was heavily dependent on textile mills. Maybe you’ve heard of a man named “Shoeless” Joe Jackson. He played a bit of baseball.

Well, Joe didn’t go to elementary school, because his family needed him to work in the mills so they could make ends meet. He never learned to read or write, so his wife signed his papers for him. Just a century ago there were plenty of kids like Shoeless Joe.

These days kids in South Carolina go to school, while many of their parents work in the BMW plant instead of the textile mill. More than 110,000 people in the state work for foreign employers. These jobs pay well, too. The federal government’s Bureau of Economic Analysis says the earnings of persons employed in South Carolina increased 5.7 percent from 2004 to 2005.

The Organization for International Investment, a business association, calculates that “U.S. subsidiaries of companies headquartered abroad support 5.1 million American jobs, with an annual payroll of close to $336 billion.” But you can’t attract these “in-sourced” jobs if you try to seal our economy in amber and protect every existing job, as so many presidential candidates seem to want to do. Should we have started subsidizing horse-and-buggy makers when cars were invented?

Look at Europe, where countries such as France have tried to protect every existing job by making it almost impossible to fire an employee, no matter how poorly he performs. As a result, companies are reluctant to hire new people, so the country suffers from high unemployment (8.3 percent in the third quarter of this year). And unemployment is even higher among younger people, those who ought to be the workers of the future. One in five people under 25 can’t find a job.

History is a terrific tool. We should learn from it and make sure we keep moving forward with optimism.

Ignore the fearmongers on the campaign trail. It’s impossible to freeze an economy without freezing new people out. Life in the United States is better today than it’s ever been, and it’ll be better still next month, next year and in decades to come.