To Buy or Not to Buy? The fine art of deciding when to spring for what you want.

Some expenses are no-brainers -- food, shelter, heat. Others are a seemingly endless source of doubt and equivocation: morning lattes, new stainless flatware, a long-dreamed-of trip to Thailand. These are the expenses that can leave us (me) anxious and conflicted.

Despite the old saying, research shows that money can buy happiness, so figuring out how to make the most of scarce discretionary dollars is an effort well worth making, say experts in the burgeoning field of positive psychology. "If Money Doesn't Make You Happy, Then You Probably Aren't Spending It Right" is the title of an article co-authored by Harvard professor Daniel T. Gilbert, author of the nationally bestselling Stumbling on Happiness. Among the reported findings:

• Purchases made with the primary goal of acquiring life experiences out-perform those made with the goal of acquiring a material good or object.
• Spending that improves our connections with others, such as buying a friend a gift or taking them to dinner, yields outsized happiness returns.
• Small, frequent pleasures are a better bet than fewer big-ticket splurges.

But such guidelines only take you so far. While research findings speak to statistical norms, they won't always speak to you. That's why author Laura Vanderkam counsels paying close attention to tracking what actually makes you happy, as she herself has taken to doing. "These days, I buy more little pleasures, like lattes and flowers, and spend more on gifts and on getting together with friends. I spend more on something when I can identify the specific proprietor or creative type who would benefit from my purchase," she writes in the new book All the Money in the World: What the Happiest People Know About Getting and Spending.

[Related: The Secret to Living Well on Less]

Some years back, personal finance guru David Bach, author of The Automatic Millionaire and other bestsellers, made a splash by coining the (now-trademarked) term Latte Factor to describe what he views as a common American tendency to fritter away close to $1 million on coffee and other ephemera in the course of a lifetime. But along with its questionable fiscal assumptions -- guaranteed 10 percent returns, anyone? -- this attitude fails to take into account the real and ongoing importance of small pleasures in daily life. "[A]cross many different domains, happiness is more strongly associated with the frequency than the intensity of people's positive affective experiences," Harvard's Gilbert and his co-authors concluded.

That said, for all the acknowledged value of small daily pleasures, we're also likely to weigh the occasional big-ticket item. In such cases, I've found it helpful to use this whimsical query adapted from blogger Havi Brooks: "Is this purchase likely to make life better for Slightly Future Me?" For reasons that I don't quite understand, this tends to leave me clearer. I also try to remind myself that, while I'm making the best decision that I can, I can't guarantee how my choice will play out. Like all investments, my happiness portfolio entails a certain level of risk. Assessing my risk tolerance has to be part of the equation.

[Related: Welcome to Plan B Nation]

Based on these reflections and calculations, I've finally embarked on planning that long-awaited Thailand trip. (I'm taking added inspiration from research findings cited by Vanderkam that vacation anticipation boosts happiness levels for another eight weeks.) Ditto for acquiring a new set of flatware: Yes, at one level this is an object, but at another, it will become part of my daily experience, and I'm pretty sure that in this way it will give my spirits a regular lift -- just as the pottery plates I bought last year still do at meals.

In the meantime, coffee at my favorite cafes will keep its place in my budget. While a latte certainly has its cost, the happiness it buys is priceless.