When I was a kid, I recall that a popular expression was “same difference.” It meant that two choices were essentially interchangeable. Despite its informality, it turns out that this idea can be helpful in financial planning. While some financial decisions are very important—and thus warrant careful analysis—others make much less of a difference. In those cases, additional analysis tends to contribute little. According to one study, it can even be counterproductive. Below are several such cases, where extensive analysis is often less important than it might seem.

Asset allocation. When it comes to building a portfolio, personal finance author Mike Piper sums it up this way: “Asset allocation is like making a fruit salad…If you put in more blueberries, nothing magical happens, nor is there any disaster.” Piper argues that the same applies to building a portfolio. It’s simply not worth getting too hung up on the details. This is especially true when it comes to the world of investment choices, where it’s impossible to know the result of a given decision without the benefit of hindsight.

The number of potential decisions is endless. Should you tilt your portfolio toward small-cap or value stocks? Should you stick with the simplicity of the S&P 500 or opt for a broader total-market fund? Should you add a sliver of real estate or of commodities? Should you opt for the safety of government bonds or venture into corporate debt?

At the end of the day, as long as none of these decisions takes your portfolio too far in any one direction, the difference in long-term returns will likely be minor. What’s much more important is to get the big decisions right. How much you hold in stocks versus in bonds will have far more of an impact than whether you choose to overweight one corner of the market or another.

Fund choices. As I noted last week, there are more than 3,500 exchange-traded funds available to U.S. investors. Within many categories, there are hundreds of choices. Consider the most basic asset class: large-cap domestic stocks. The obvious choice is a fund that tracks the S&P 500 Index, but there are many alternatives. There’s the Dow Jones Industrial Average, the Russell 1000, the MSCI US Prime Market 750 Index and the Wilshire 5000. Which should you choose?

Run the numbers using a tool like Portfolio Visualizer, and you’ll find the correlations among these indexes are all between 0.95 and 1, meaning they move nearly in lockstep. And their annual returns are within one percentage point of one another. The upshot: While these indexes aren’t all identical, they’re awfully close, so no one should lose sleep trying to choose among them.

Pension choices. These days, only a minority of workers have the benefit of a traditional pension. For those who do, though, this benefit requires a long list of decisions. The first question is the most fundamental: Employees can claim their benefit as a single lump sum or in the form of guaranteed monthly payments for life.

Those who accept the lump sum can roll it over into another retirement account and manage it the way they do the rest of their portfolio. But for those who opt for the monthly payments, there are several additional options to consider.

Workers who are married can choose a survivor benefit—typically 50%, 75% or 100% of the worker’s own benefit. Those who worry their spouse might predecease them can choose a “pop-up” benefit, which increases the worker’s own payments if their spouse dies early. And for those who worry about their own longevity, some pensions offer benefits that are guaranteed for a period of years.

If this all seems complicated, it is. And because this choice is irrevocable, it tends to induce stress. But here’s what’s surprising: If you run the numbers, the differences are often not as significant as they might seem. To understand why, let’s look at the math used to evaluate complicated choices like this.

Present value analysis allows us to compare the value of a dollar today with the value of a dollar received at some point in the future. Intuitively, it makes sense that a dollar you receive today would be worth more than a dollar next month or next year. And a dollar received further in the future—say, in 10 years—would be worth even less than that. Using a “discount rate” of 7%, which is what you might earn by investing a sum of money today, the value of a dollar today falls to just $0.51 after 10 years and to just $0.26 after 20 years.

This is relevant to pension analysis because it reveals the diminishing value of payments received far in the future. Let’s look at a simplified example. Suppose a pension offers these two options:

• $3,000 per month for life with no survivor benefit
• $2,700 per month for life with a survivor benefit of 50%

The difference between these two options—$300 per month or $3,600 per year—might seem significant today. But because of the present value dynamic described above, it isn’t nearly as significant as it might seem. Using that same 7% discount rate, that $300 difference would shrink to just $152 in 10 years and $77 in 20 years. And of course, the survivor benefit would potentially extend the number of years of payments, albeit at a lower rate.

The bottom line: You should never give financial decisions short shrift, but as these numbers reveal, it may not be worth belaboring the decision. Especially because of the uncertainty of longevity, most pension choices end up being in the same neighborhood.

Social Security. When it comes to Social Security, retirees can claim their benefit at any time between ages 62 and 70. For each year the retiree waits, the monthly benefit increases. But each year a retiree waits is also a year with no benefit at all. As a result, retirees need to guess how long they’ll live, and that’s never easy. Is there another way to make this decision?

If you’re unmarried and in generally good health, the decision is straightforward: Most everyone—myself included—recommends waiting until age 70 for the largest possible benefit. But if you’re married, should you both wait until 70? At first glance, that might seem like the logical choice—and that’s what the math says. But sometimes the differences are insignificant.

When most people run the numbers, what they find is that there’s only a modest difference for the lower-earning spouse if he or she claims a bit earlier—say, at 68 or 69 instead of 70. Why? For starters, none of us knows how long we’ll live, so claiming earlier always has an inherent advantage. And because of the present value effect, the true value of forgoing benefits today for a larger check later may be smaller than it appears.