Everything we do has a cost in terms of time, money or energy. This concept of opportunity cost is an important one. The more efficiently we use our resources, the more we have available for other things. In this way efficiency is an important tool we use to increase our freedom.
I loosely define freedom as the ability to spend my time as I choose. I trade my time (life energy) for money, and hope to derive happiness from trading this money for something else in the future. When we are inefficient with our money or other resources, we are really throwing away time which is our most valuable commodity.
Efficiency will only take us so far though. We can only become so efficient before we see diminishing returns on our investment. At some point we have to think differently.
As far as I can tell the term stacking functions originated or gained popularity in the permaculture community. I define it as a single input or element that serves multiple functions. When efficiency is no longer enough, we can use this more advanced tool. This is important because it is another way to maximize our freedom.
Let me give an example of the diminishing returns of efficiency:
Cars have a certain energy efficiency we measure in miles per gallon.
If you drive 10,000 miles per year, and your car gets 20 mpg, you use 500 gallons of gasoline.
At $3/gal that’s about $1500.
Divide this number by your true hourly wage and this is how much life energy you trade for this gasoline.
Example: At $30/hour you are spending 75 hours of your life every year working to pay for gas.
It’s pretty easy to make a car that gets 20 mpg. Even big lumbering trucks and minivans can sometimes accomplish this.
Let’s upgrade though. If we increase efficiency to 30 mpg we use 333 gallons per year or about $1000. We save $500/yr. Not bad, and not too difficult either.
If we bump up to 40 mpg there is some thought that has to go into the design of the car. Lighter materials, better engine design, aerodynamic considerations. It is much tougher to go from 30mpg to 40mpg than it is from 20mpg to 30mpg, just ask the car manufactures. But we are saving money on gas, right? At 40 mpg we are down to 250 gallons which is $750. We save $250…
Wait a minute. What’s going on here? The first 10mpg we shaved off saved us $500, but the next 10mpg only saved us $250? This can’t be right, can it?
What if we keep going? At 50 mpg we are getting into high tech fancy stuff. We are down to 200 gal at a price of $600. Only a savings of $150 per year compared to the 40 mpg car.
I even made you a super fancy table to illustrate my point:
|Miles per Gallon||Gallons per year at 10k miles||$/yr @ 3$/gal|
Alright philosopher, I get it. Where are you going with this?
At some point more efficiency does not make sense. We start spending more time and energy becoming efficient just for the sake of it. There is a diminishing return on our investment. If our goal is to save money on gas we have to look beyond efficiency. This is where we can stack functions.
What if instead we just try and drive less? Maybe we start combining trips in the car, carpool, walk and bike more, move closer to work, telecommute 1 or 2 days a week, etc. Maybe we could combine dropping the kids off at soccer practice with doing grocery shopping at the store which is on the way.
I used to drive everywhere without thinking about the cost of my time, energy and actual monetary costs. If I needed something I would drive 5 miles and take a half hour of my time. I would give no thought to stacking functions. Now at this point in my life the monetary costs are negligible, but my time is becoming more valuable.
By the way, it probably costs you 30-50 cents per mile you drive (plus whatever you value your time at). It is worthwhile sitting down and doing these calculations for yourself. You may start buying closer to home even if you have to pay a few more dollars for things.
A few more examples.
Think of a chicken.
A chicken will act as a source of food (eggs and meat), pest control (eating bugs), fertilizer (manure) and entertainment (have you ever spent time watching chickens? Better than most movies these days). The chicken serves multiple functions are the same time. It is similar to running 5 errands all at once rather than making 5 separate trips.
Turkeys are pretty entertaining too.
Another example is a fruit tree…although not nearly as entertaining as the chickens.
A fruit tree will eventually give you much more value in fruit each season than the original purchase price. It may also provide you with an increase in property value, and the asset (fruit) is not taxed. It is like getting a tax free dividend. Not only do you get the economic benefit of free fruit, but if strategically placed will save you money on air conditioning if it shades a window in the summer.
I will give you a final example. For the past few years I have intermittently been commuting to work via bicycle. It is roughly 30 minutes each way on my bike, and about 15 minutes by car. Many days before this I would commute by car, come home and…go on a bike ride for exercise. I know, kind of ridiculous. By combining both activities I get 60 minutes of riding in while saving 30 minutes driving. This is free time that falls in my lap. Additionally, I save money by not spending as much on gas, maintenance and depreciation on my car. It is a small change, but the small things add up.
When stacking functions in your life, be creative. Think of all the benefits: Monetary, time savings, happiness, health benefits, etc. There will be areas of value you have not considered before.
Your homework (yeah, this blog has occasional homework) is to find the ways that you can stack functions in your life. Please share in the comments below so we can all learn together.