Green initiatives are often promoted as paying for themselves, leading to widespread acceptance. Why wouldn’t we do things that also have environmental benefits if they have little or no financial cost? When considering such matters, it’s important to use conservative estimates of the true costs.

According to a recent Newsweek article, Are We Underestimating the Cost of Going Green, author Robert J. Samuelson argues that in far too many cases, computer models make assumptions that are much too optimistic. As someone who models complex systems regularly for my day job, I can tell you how quickly the accuracy of a model can diminish when faulty assumptions are made. Even the best of models is only as good as its worst assumption.

I am not suggesting that we should blatantly disregard modeled results. In fact, they are often highly accurate and superior to other estimation methods. I simply try to approach all cases where things seem too good to be true with a moderate amount of skepticism. Would you blindly trust a stock-picking algorithm that promised above-average returns for below-average risk? No, you need to balance modeled results with known laws and rules, such as, it takes more risk to achieve more reward.

As stated previously, there are certainly non-monetary reasons to transition to a greener lifestyle. On a micro scale, you often see monetary benefits as well. A simple change, like transitioning to energy-efficient appliances, really can save you more than the cost of the upgrade over time. On a larger scale, coming to accurate cost conclusions can be more difficult. Green initiatives are also a politically charged topic. Supporters can produce highly favorable models as quickly as denouncers can produce ones with conflicting results. A minor change of assumptions can have a major effect on the results. So take the steps you feel are necessary to achieve a greener lifestyle, but remember that it will probably cost more than the supporters suggest and less than those opposed would have you believe.

Did a green project you implemented cost more or less than you expected?

If you’re like me, you probably have a half dozen or more of those little rewards cards dangling from your key ring. Mine are for the drug, grocery, book and sporting goods stores I visit the most often.

Recently Panera Bread did away with its stamped card for a free cup of coffee after purchasing so many in favor of one of those rewards cards. While the company didn’t ask for any of my personal information, most card issuers do.

By using these “membership” or “loyalty” cards, you receive discounted prices, points or cash back toward future purchases that you otherwise wouldn’t receive.

I am a member of the group that has provided my personal information multiple times. I look for my Extra Bucks at the bottom of my CVS receipt at the end of each quarter. And I have probably visited Panera Bread more since I received the card now that the store offers me a free pastry or coffee after so many lunches I buy.

When you load groceries into your cart, you're probably not worried about whether your supermarket chain is compiling a profile of you based on what you buy, and storing that information for its own use. After all, who cares if you buy one brand of laundry detergent over another, or prefer name-brand frozen dinners rather then store brands?

Supermarket chains care and so does your drugstore. While these discount cards offer you what seem like great bargains, stores are using them to keep tabs on what you purchase, how often you shop, and what your buying preferences are.

According to a 2004 poll conducted by Boston University's College of Communication, 86 percent of American shoppers use some form of store loyalty or discount card, and the majority of them say the benefits of the card are worth giving up some privacy.

While retailers maintain that they only analyze collective data, some critics have questioned whether it isn’t just a matter of time before records of individual consumer preferences are either sold to third parties or made available to investigatory agencies. In fact, some apparently isolated examples of that have already occurred.

For example, in a 2004 Washington state case, a suspected arsonist was arrested after police tracked down a fire-starter unit with a Safeway label attached. Safeway provided police with the suspect’s purchase history, revealing that he had bought a fire starter a month earlier. The charges were later dropped, but the point is that the store gave access to the customer’s personal information to authorities.

Are you willing to surrender some personal information about yourself to save money?

With consumers trying to stretch each dollar further, it should come as no surprise that thrift stores are seeing a surge in sales.

According to USA Today, February revenues at Goodwill Industries stores increased 7.2% over last year. A similar increase was seen at a group of Salvation Army thrift stores. The rise in sales is likely due to an influx of new customers who are turning to thrift stores out of necessity or an increased awareness of their financial situations, due to job loss or the general state of the economy. Thrift store regulars may also be increasing their own reliance on the stores as well.

One downside of strong sales is that all thrift store shoppers may find great deals harder to come by. Rising sales means that fewer items are left for purchase. Donations to thrift stores are also way down. The cited article said that Salvation Army donation pickups in six states for the first eight weeks of 2009 were down nearly 13% from last year. Higher value donations, such as furniture and major appliances, are down the most. This is likely tied to the downturn in the housing market as well as the slow economy. Lower supply and higher demand generally raises prices, but in the case of thrift stores – whose prices generally remain unchanged – this situation simply results in a smaller supply of high quality items.

Though rising thrift store sales may be driven by need, this good financial habit can be continued when situations improve. As the economy rebounds, you’ll likely be able to find even better thrift store deals as other consumers return to their traditional retailers of choice. Their newfound prosperity may also increase the quality and quantity of donations.

Have you visited a thrift store for the first time or relied more heavily on the products they offer?

Just a few weeks ago, my plane landed into a biting ice storm in New York City. My itinerary? Salvador, Brazil to New York City; that is, a boiling summer to a caustic winter. Hearing the chuckles of nearby passengers as I walked towards the ATM, clothed only in flip flops, Bermuda shorts, and a thin white T-shirt, I suddenly realized that there are no Wells Fargo ATMs in all of New York City.

For the first time ever, I was asked to pay an ATM fee, something I’ve never had to do before. I paid the $2.50 to withdraw money, and when I arrived at my hotel and checked my bank statement, I realized that Wells Fargo had ALSO charged me an additional $2.50 for using an outside ATM, bringing my one-time withdrawal fee to a total of $5, or about 5% of my entire withdrawal.

In California, where I used to live, of course I never experienced this problem. I used only Wells Fargo ATMs and never had to deal with any fines. I was surprised, though, when I mentioned this story to family and friends and realized that this situation wasn’t as uncommon as I thought. Some friends had been living in New York City for almost a year without ever figuring out a way to escape the bank fees!

Are you in a situation where you find yourself paying insane bank fees for withdrawals? If you are losing $5 per withdrawal, you are spending hundreds, maybe thousands of dollars a year in bank fees! This is money you could spend paying off your debt or traveling around the world!

My solution to this particular problem is to use Wachovia ATMs in New York City, since Wells Fargo bought their bank and now offers free ATM withdrawals. However, you might be spending tons of money because you find yourself without cash at gas stations or other places. How much could you save by withdrawing money ahead of time?

Do you find yourself paying a lot in ATM fees? What do you do to handle them? How do you solve this problem?

Emergency funds are an important part of your financial plan, covering an unexpected expense or normal expenses during a period of reduced income. But many of the situations traditionally associated with emergency funds aren’t really unexpected expenses and can thus be handled in a different way.

Many people confuse irregular expenses with unexpected expenses. An irregular expense is typically known, or can be estimated beforehand, but occurs on an irregular schedule. Things like auto repairs, medical costs, household repairs, and even gifts fit this description. One of the nice features of tracking your expenses and using a budget is that you start to get a better understanding of such expenses.

Take gifts, for example. Obviously, birthdays and holidays are gift-giving occasions that are known ahead of time. By tracking your expenses, you’ll probably see other trends emerge as well. You may notice that you get invited to a few weddings each year, or that a handful of friends have babies, etc. Once you get a sense of the total amount required in a typical year, you’ll be able to add that amount to your budget.

If you have an expense item in your budget for each irregular expense category, then savings will happen automatically. If you budget $1,200 a year for auto repairs, you’ll save $100 each month that a repair isn’t needed, and that money will be available when the inevitable repair does come up. If the repair is needed early, before you have saved enough, then you can dip into your emergency fund, but then the money you allocated towards repairs in future months should be used to repay the amount you took from that fund.

I have many expense categories in my budget that I rarely use. Most months I spend nothing and the budget surplus accumulates in savings. Then, when an expense is necessary in that category, the money is already in place. You shouldn’t have to rely on an emergency fund to cover irregular expenses, since they can be planned for in a budget. That will allow you to save your emergency fund for true emergencies, such as the loss of your job.

Do you budget for irregular expenses that others define as “emergencies”?