This week’s “Daily Journal” guest columnist is Jenna Ashley Robinson, E.A. Morris Fellowship Assistant for the John Locke Foundation.

I got a new car last month. Because I travel a lot, I chose the Scion xA, which, among its other features, gets 32 mlies per gallon in the city and 38 mpg on the highway, based on 2006 EPA mileage estimates.

With gas prices still hovering over $2.00, I haven’t yet regretted my decision to buy a small, efficient car. And, if I didn’t know that oil is a fungible commodity, I’d get to feel “socially responsible,” too. After all, I’m using less oil and putting fewer pollutants into the environment.

Would I be better off with a Hybrid? At this point, I’m interested only in getting the biggest bang for my buck. Environmental concerns come second. However, since hybrid vehicles claim long-run savings based on greater fuel efficiency, it’s worth further investigation.

Doing a few very crude calculations (with apologies to all my past econ professors), I find that I’m saving money with my all-gas car. Comparing my Scion (a four-door hatchback) to the popular Toyota Prius Hybrid (a four-door sedan), I find that driving the Prius saves 0.01 gallons of fuel per mile driven. That’s right: 1/100th of a gallon. Color me unimpressed.

Adding up the fractions of a gallon doesn’t improve the picture. In order to save money by choosing a hybrid, I would have to use 3,326 gallons of gas in the time I own the car. In order to use all those gallons, I’d have to drive the Prius for more than 332,000 miles. And that’s without discounting the future stream of savings on gas; after all, saving a dollar on gas in ten years might be worth practically nothing to me now.

Those projections also assume that gas at the pump stays at about $2.65/gallon in today’s dollars (EIA’s current estimate). However, as we’ve seen in recent weeks, that’s not always the case. I filled up this week for only $2.09. And even if gas prices shoot up to $3.00/gallon, I’d still have to drive a Prius more than 265,000 miles to save money over my all-gas Scion.

To be fair, though, I should compare apples to apples. Fortunately, Honda makes gasoline and hybrid versions of its Civic sedan. In the Civic comparison, the hybrid fares even worse. The hybrid Civic outpaces its gasoline counterpart by only 14 mpg and costs about $7,000 more. That difference requires driving 336,762 miles to overcome. So if you’re eyeing the Civic Hybrid, you should save your money by buying the all-gasoline version.

Moreover, the cost of repairing a hybrid car can be prohibitive. Not to mention that the slow future savings in gasoline might not offset the initial outlay of $7,000 more for a hybrid model, given that a dollar is worth more now than in the future. In any case, those saved future dollars might go to paying interest if you finance the higher cost of a hybrid vehicle.

So, if the goal is simply an efficient, economical vehicle, buying a hybrid probably isn’t the best solution. The market provides plenty of available options that cost far less than any of the hybrids currently available. Some of the most affordable and efficient are the Honda Fit, the Toyota Yaris, the Nissan Versa, the Ford Focus, and the Chevy Aveo, most of which have appeared on the U.S. market in the past few years as a response to rising gas prices.

And the market continues to offer new solutions. This year, Paris hosted the eighth annual Michelin Challenge Bibendum, a gathering of auto manufacturers, researchers, inventors, and free thinkers from all over the globe to explore the idea of “Sustainable Mobility.” Some possibilities exhibited included hybrids, diesel hybrids, flex-fuel vehicles, clean diesels, and fuel cell vehicles. Not to mention that simply using lighter body styles with conventional technology can save a substantial amount of gas and money.

The good news is that markets drive innovation. I expect to see more choices in the future, driven by consumer demand for better performance, higher mpg ratings, and affordable prices. In the end, it will be supply and demand that save the environment, not government regulations. And maybe in 10 years, when I’m purchasing my next new car, buying a Hybrid will be a wise economic decision instead of just an environmentally friendly one.