I’ve written previously about the importance of permanent habit change in both managing your finances and your body weight. After finishing Smart People Don’t Diet by Charlotte Markey and then reviewing my Kindle highlights, please allow me to compare weight management and money management one more time.

I’m going to keep it simple; I’ll quote exact sentences from the book, and then tweak them ever-so-slightly to magically transform them into personal finance wisdom. Here’s a quote about her overall reason for writing this book:

Psychologists like me have been doing research about eating and weight loss for over a hundred years, and thousands of studies about these issues have been published. Scientists in related fields such as nutrition, medicine, and community health have also been studying and publishing about these issues for a very long time. And yet it seems that the most marketable and even outlandish ideas are what get the most attention when it comes to weight loss—not necessarily the ideas that are really going to work!

Here’s my Mad Libs version (all changes are bolded):

Finance academics like me have been doing research about investing for over a hundred years, and thousands of studies about these issues have been published. Scientists in related fields such as economics and behavioral psychology have also been studying and publishing about these issues for a very long time. And yet it seems that the most marketable and even outlandish ideas are what get the most attention when it comes to investing—not necessarily the ideas that are really going to work!

Sounds about right to me. Now, the recommended first step is to track your eating with a food diary:

Phase 1 is all about taking inventory and getting to know yourself—a critical first step. There should be no sense of deprivation when you follow the instructions for Phase 1. Phase 2 is when you’ll start to actually make changes to your eating behaviors.

In the same way, my recommended first step has been to track your spending with a daily log. There is virtually no change needed!

Phase 1 is all about taking inventory and getting to know yourself—a critical first step. There should be no sense of deprivation when you follow the instructions for Phase 1. Phase 2 is when you’ll start to actually make changes to your spending behaviors.

However, many successful people don’t need to keep up this daily tracking forever.

This is all common sense, but it is also supported by research: keeping a mental record of what you eat, or “counting” what you eat, is exhausting. This is one reason I don’t recommend constantly counting calories or counting anything as part of a long-term approach to weight management: food choices shouldn’t add to your mental fatigue.

The key is to measure your baseline and then make incremental but permanent changes. Nowadays, I still add up my expenses at the end of each month, but I don’t track anything on a day-to-day basis.

This is all common sense, but it is also supported by research: keeping a mental record of what you spend, or “counting” what you spend, is exhausting. This is one reason I don’t recommend constantly tracking every expense or counting anything as part of a long-term approach to money management: financial choices shouldn’t add to your mental fatigue.

Here are tips on creating better habits that won’t suck up all your willpower:

You don’t need to squeeze your own oranges to make juice; just eat an orange. You don’t need to make homemade bread; just buy whole-grain bread. It is okay to rely on frozen fruits or veggies to ensure that you eat enough each day. If you want to change your habits for the long-term, stick to a plan that is simple and create food routines. Simple is sustainable.

Simple is sustainable, I like that phrase!

You don’t need to analyze the balance sheets of individual companies; just buy an index fund. You don’t need to remember to manually save every month; make it automatic with scheduled online transfers to your IRA and/or 401k. It is okay to rely on Mint.com or PersonalCapital.com and credit/debit cards to track your overall spending. If you want to change your habits for the long-term, stick to a plan that is simple and create financial routines. Simple is sustainable.

Finally, a nice little summary. (The book has a lot of good advice, but it is a little repetitive.)

What I recommend to people to help them to lose weight is not always sexy, but it is what works. Weight-loss books change; most of them don’t stick around because they don’t work. To be healthy and lose weight, you have to change your habits. You also have to understand why you are eating. Convenience, habits, and our emotions are all an important part of our food choices.

What I recommend to people to help them to save and invest wisely is not always sexy, but it is what works. Personal finance and investing books change; most of them don’t stick around because they don’t work. To save prudently and achieve financial freedom, you have to change your habits. You also have to understand why you are earning and spending. Convenience, habits, and our emotions are all an important part of our financial choices.

Here’s another data point on the debate on how often to rebalance your portfolio to your target asset allocation. Econompic Data writes about rebalancing a portfolio back to 60% S&P 500 / 40% Barclays Aggregate Bond index from 1976-2014 and finds that rebalancing every 3 years actually produced slightly better average annual returns that rebalancing monthly (via Abnormal Returns):

Momentum is cited as a potential reason why this works. Looks good at a glance, but look at that y-axis. We are comparing 10.3% and 10.2%. Is that really significant?

I would point out that in a previous Vanguard research article, a similar backtest was done on a 60/40 Broad US Stock/Broad US Bond portfolio rebalanced across various thresholds from 1926-2009. Their conclusion (emphasis mine):

We found that no one approach produced significantly superior results over another. However, all strategies resulted in more favorable risk-adjusted portfolio returns when compared with returns for portfolios that were never rebalanced.

From a 2008 paper from Dimensional Fund Advisors:

Aside from avoiding excessive trading, there are no optimal rebalancing rules that will yield the highest returns on all portfolios and in every period.

From advisor and author William Bernstein:

The returns differences among various rebalancing strategies are quite small in the long run.

Instead of there being a benefit to rebalancing less often, it may just be safer that the frequency doesn’t matter. On the other hand, given the potential cost of rebalancing from taxes, commissions, and bid/ask spreads perhaps lowering the frequency doesn’t hurt.

I think the most important thing to note is that in every test case above, the rebalancing was done on a strict schedule and without emotion. The problem you are really trying to avoid is being afraid buy whatever has been getting crushed and selling what has been doing awesome. There’s that behavioral/emotional component again.

As for me, I try to check my portfolio once a quarter, but rebalance no more than once a year. An annual frequency is as easy to remember as your birthday, it’s not too often and not too seldom, lots of smart people are proponents, and it gives me the opportunity to do tax-loss harvesting. I use tolerance bands such that if my major asset classes are off by more than 5%, then I will rebalance. Otherwise, I “rebalance lite” year-round using any new money to buy underweight asset classes.

Quick question – What was the highest value ever for your investment portfolio? Now, what was the value exactly a year before that? You probably know the answer to the first question, but not the second, even though both have little to do with your final portfolio value.

I am currently reading the e-book Global Asset Allocation by Meb Faber and he had a good observation that I don’t recall ever expressed in this specific manner (emphasis mine):

It is a sad fact that as an investor, you are either at an all-time high with your portfolio or in a drawdown – there is no middle ground – and the largest absolute drawdown will always be in your future as the number can only grow larger.

We tend to carry the highest value of our portfolio around in our heads because of the powerful cognitive bias of anchoring. Let’s say that 10 years ago you started with $20,000 and today with your contributions and investment growth your total is $100,000. If next year your portfolio experiences a drawdown to $80,000, you’ll probably identify your portfolio as being 20% down from $100,000, as opposed to a 400% increase from $20,000. $100,000 is “what you had” and you will forever be anchored to that number, even if for it only lasted just for a day.

That is, until you reach another all-time high (yes! $105,000) and that will be your new anchor. (This applies to individual holdings as well – I’ve found this especially pervasive when using brokerage smartphone apps that allow me to frequently check in with just a tap.)

If your portfolio is anything like mine, it has been repeatedly been hitting all-time highs for a year or two. The problem is, sooner or later, there is a 100% chance I’ll be stuck in a prolonged drawdown phase. I will think about my high-water value every time I check my statements (which is why perhaps it is better not to check your investment value much more than once a year). I will question my existing asset allocation and how to invest my new money.

Now add in loss aversion – the other finding from behavioral economics that people feel the pain of losses much more severely than the pleasure of gains (studies suggest we hate losses roughly twice as much as gains).

That means drawdowns are always lurking around the corner, and we hate them twice as much as any investment gain. It’s no wonder that investors are often their own worst enemies by not sticking to their investment plans.