In the spring of 2001, my son was recruited by a Wall Street investment firm. I naturally think my son is brilliant, but I remember being puzzled at the time. He had never taken an economics course and had never showed any interest in business. He was a math major. What was his appeal to Wall Street?

This year the question has been answered. That spring George W. Bush and the Republican Congress had just come into office. They were in the process of cutting taxes by hundreds of billions of dollars and reducing regulatory oversight of the banking system. Rich people were overloaded with money to invest. The Wall Street firms wanted mathematicians to figure out new ways to slice and dice existing assets and risks to repackage and resell them over and over again. It was a great game. Everyone made money hand over fist.

There were just two problems. First, this orgy of spending didn’t do anything for the real economy. It didn’t improve roads. It didn’t make houses more affordable. It didn’t keep our mills in rural Maine running strong. It didn’t build the wind and solar power industries. It didn’t strengthen the dollar. It didn’t improve the balance of trade. It didn’t reduce the deficit. It was a spending spree on the decks of the Titanic, buying and selling chairs, but not creating any new economic value.

Second, as we are now finding out, it could not last. The ship has sunk.

Now it is seven years later, and we have another election. We have a new Republican presidential candidate. But John McCain’s economic program is a carbon copy of the one George W. Bush implemented seven years ago. McCain promises to extend and deepen Bush’s tax cuts for the well-to-do, costing an estimated — by the Brookings Institution — $3.6 trillion in the next 10 years. For the top one-tenth of 1 percent of all earners, i.e., investment bankers and CEOs, the tax reduction would be, on average, $680,000 by 2012. McCain also brings a lifelong commitment to deregulation of business.

The question we voters have to answer is this: How did all this work out last time? Is our economy better off than in 2000? Are food and energy and housing and health care more affordable? Are our businesses stronger and paying higher salaries? Are our schools and roads and communities in good shape?

Why would we want to continue this set of economic policies for another four to eight years? As the old saying goes, “Fool me once, shame on you. Fool me twice, shame on me.”

Barack Obama represents a change in policy. Usually change represents risk. But this year is different. This year staying the course is what is risky. What is safe is making a change.

It is more than safe. It’s common sense. Common sense says that we should invest in wind and solar power. Common sense says that we should reduce taxes for middle-class people who have been pounded in the past few years and increase it on the top 1 percent. Common sense says that we need to responsibly end the Iraq war and use the money at home. Common sense says that we need to regulate Wall Street so that taxpayers and investors are never again left with the bill after the party is over.

Barack Obama would bring in the Clinton team of economic advisers who brought the country eight years of economic growth and turned a federal deficit into a surplus.

This year the safe choice for our economic future is not the familiar old face. If economic growth and a secure retirement are your concerns, the common sense vote is for Barack Obama.

Frank O’Hara is a public policy consultant from Hallowell.