Daylight Savings Time is pointless and harmful

Nov 12, JDN 2458069

As I write this, Daylight Savings Time has just ended.

Sleep deprivation costs the developed world about 2% of GDP—on the order of $1 trillion per year. The US alone loses enough productivity from sleep deprivation that recovering this loss would give us enough additional income to end world hunger.

So, naturally, we have a ritual every year where we systematically impose an hour of sleep deprivation on the entire population for six months. This makes sense somehow.
The start of Daylight Savings Time each year is associated with a spike in workplace injuries, heart attacks, and suicide.

Nor does the “extra” hour of sleep we get in the fall compensate; in fact, it comes with its own downsides. Pedestrian fatalities spike immediately after the end of Daylight Savings Time; the rate of assault also rises at the end of DST, though it does also seem to fall when DST starts.

Daylight Savings Time was created to save energy. It does do that… technically. The total energy savings for the United States due to DST amounts to about 0.3% of our total electricity consumption. In some cases it can even increase energy use, though it does seem to smooth out electricity consumption over the day in a way that is useful for solar and wind power.

But this is a trivially small amount of energy savings, and there are far better ways to achieve it.

Simply due to new technologies and better policies, manufacturing in the US has reduced its energy costs per dollar of output by over 4% in the last few years. Simply getting all US states to use energy as efficiently as it is used in New York or California (not much climate similarity between those two states, but hmm… something about politics comes to mind…) would cut our energy consumption by about 30%.

The total amount of energy saved by DST is comparable to the amount of electricity now produced by small-scale residential photovoltaics—so simply doubling residential solar power production (which we’ve been doing every few years lately) would yield the same benefits as DST without the downsides. If we really got serious about solar power and adopted the policies necessary to get a per-capita solar power production comparable to Germany (not a very sunny place, mind you—Sacramento gets over twice the hours of sun per year that Berlin does), we would increase our solar power production by a factor of 10—five times the benefits of DST, none of the downsides.

Alternatively we could follow France’s model and get serious about nuclear fission. France produces over three hundred times as much energy from nuclear power as the US saves via Daylight Savings Time. Not coincidentally, France produces half as much CO2 per dollar of GDP as the United States.

Why would we persist in such a ridiculous policy, with such terrible downsides and almost no upside? To a first approximation, all human behavior is social norms.

Elasticity and the Law of Supply

JDN 2457292 EDT 16:16.

Today’s post is kind of a mirror image of the previous post earlier this week; I was talking about demand before, and now I’m talking about supply. (In the next post, I’ll talk about how the two work together to determine the actual price of goods.)

Just as there is an elasticity of demand which describes how rapidly the quantity demanded changes with changes in price, likewise there is an elasticity of supply which describes how much the quantity supplied changes with changes in price.

The elasticity of supply is defined as the proportional change in quantity supplied divided by the proportional change in price; so for example if the number of cars produced increases 10% when the price of cars increases by 5%, the elasticity of supply of cars would be 10%/5% = 2.

Goods that have high elasticity of supply will rapidly flood the market if the price increases even a small amount; goods that have low elasticity of supply will sell at about the same rate as ever even if the price increases dramatically.

Generally, the more initial investment of capital a good requires, the lower its elasticity of supply is going to be.

If most of the cost of production is in the actual marginal cost of producing each new gizmo, then elasticity of supply will be high, because it’s easy to produce more or produce less as the market changes.

But if most of the cost is in building machines or inventing technologies or training employees which already has to be done in order to make any at all, while the cost of each individual gizmo is unimportant, the elasticity of supply will be low, because there’s no sense letting all that capital you invested go to waste.
We can see these differences in action by comparing different sources of electric power.

Photovoltaic solar power has a high elasticity of supply, because building new solar panels is cheap and fast. As the price of solar energy fluctuates, the amount of solar panel produced changes rapidly. Technically this is actually a “fixed capital” cost, but it’s so modular that you can install as little or as much solar power capacity as you like, which makes it behave a lot more like a variable cost than a fixed cost. As a result, a 1% increase in the price paid for solar power increases the amount supplied by a whopping 2.7%, a supply elasticity of 2.7.

Oil has a moderate elasticity of supply, because finding new oil reserves is expensive but feasible. A lot of oil in the US is produced by small wells; 18% of US oil is produced by wells that put out less than 10 barrels per day. Those small wells can be turned on and off as the price of oil changes, and new ones can be built if it becomes profitable. As a result, investment in oil production is very strongly correlated with oil prices. Still, overall production of oil changes only moderate amounts; in the US it had been steadily decreasing since 1970 until very recently when new technologies and weakened regulations resulted in a rapid increase to near-1970s levels. We sort of did hit peak oil; but it’s never quite that simple.

Nuclear fission has a very low elasticity of supply, because building a nuclear reactor is extremely expensive and requires highly advanced expertise. Building a nuclear power plant costs upward of $35 billion. Once a reactor is built, the cost of generating more power is relatively trivial; three-fourths of the cost a nuclear power plant will ever pay is paid simply to build it (or to pay back the debt incurred by doing so). Even if the price of uranium plummets or the price of oil skyrockets, it would take a long time before more nuclear power plants would be built in response.

Elasticity of supply is generally a lot larger in the long run than in the short run. Over a period of a few days or months, many types of production can’t be changed significantly. If you have a corn field, you grow as much corn as you can this season; even if the price rose substantially you couldn’t actually grow any more than your field will allow. But over a period of a year to a few years, most types of production can be changed; continuing with the corn example, you could buy new land to plant corn next season.

The Law of Supply is actually a lot closer to a true law than the Law of Demand. A negative elasticity of supply is almost unheard of; at worst elasticity of supply can sometimes drop close to zero. It really is true that elasticity of supply is almost always positive.

Land has an elasticity near zero; it’s extremely expensive (albeit not impossible; Singapore does it rather frequently) to actually create new land. As a result there’s really no good reason to ever raise the price of land; higher land prices don’t incentivize new production, they just transfer wealth to landowners. That’s why a land tax is such a good idea; it would transfer some of that wealth away from landowners and let us use it for public goods like infrastructure or research, or even just give it to the poor. A few countries actually have tried this; oddly enough, they include Singapore and Denmark, two of the few places in the world where the elasticity of land supply is appreciably above zero!

Real estate in general (which is what most property taxes are imposed on) is much trickier: In the short run it seems to have a very low elasticity, because building new houses or buildings takes a lot of time and money. But in the long run it actually has a high elasticity of supply, because there is a lot of profit to be made in building new structures if you can fund projects 10 or 15 years out. The short-run elasticity is something like 0.2, meaning a 1% increase in price only yields a 0.2% increase in supply; but the long-run elasticity may be as high as 8, meaning that a 1% increase in price yields an 8% increase in supply. This is why property taxes and rent controls seem like a really good idea at the time but actually probably have the effect of making housing more expensive. The economics of real estate has a number of fundamental differences from the economics of most other goods.

Many important policy questions ultimately hinge upon the elasticity of supply: If elasticity is high, then taxing or regulating something is likely to cause large distortions of the economy, while if elasticity is low, taxes and regulations can be used to support public goods or redistribute wealth without significant distortion to the economy. On the other hand, if elasticity is high, markets generally function well on their own, while if elasticity is low, prices can get far out of whack. As a general rule of thumb, government intervention in markets is most useful and most necessary when elasticity is low.

What are the limits to growth?

JDN 2456941 PDT 12:25.

Paul Krugman recently wrote a column about the “limits to growth” community, and as usual, it’s good stuff; his example of how steamships substituted more ships for less fuel is quite compelling. But there’s a much stronger argument to made against “limits to growth”, and I thought I’d make it here.

The basic idea, most famously propounded by Jay Forrester but still with many proponents today (and actually owing quite a bit to Thomas Malthus), is this: There’s only so much stuff in the world. If we keep adding more people and trying to give people higher standards of living, we’re going to exhaust all the stuff, and then we’ll be in big trouble.

This argument seems intuitively reasonable, but turns out to be economically naïve. It can take several specific forms, from the basically reasonable to the utterly ridiculous. On the former end is “peak oil”, the point at which we reach a maximum rate of oil extraction. We’re actually past that point in most places, and it won’t be long before the whole world crosses that line. So yes, we really are running out of oil, and we need to transition to other fuels as quickly as possible. On the latter end is the original Mathusian argument (we now have much more food per person worldwide than they did in Malthus’s time—that’s why ending world hunger is a realistic option now), and, sadly, the argument Mark Buchanan made a few days ago. No, you don’t always need more energy to produce more economic output—as Krugman’s example cleverly demonstrates. You can use other methods to improve your energy efficiency, and that doesn’t necessarily require new technology.

Here’s the part that Krugman missed: Even if we need more energy, there’s plenty of room at the top. The total amount of sunlight that hits the Earth is about 1.3 kW/m^2, and the Earth has a surface area of about 500 million km^2, which is 5e14 m^2. That means that if we could somehow capture all the sunlight that hits the Earth, we’d have 6.5e17 W, which is 5.7e18 kilowatt-hours per year. Total world energy consumption is about 140,000 terawatt-hours per year, which is 1.4e14 kilowatt-hours per year. That means we could increase energy consumption by a factor of one thousand just using Earth-based solar power (Covering the oceans with synthetic algae? A fleet of high-altitude balloons covered in high-efficiency solar panels?). That’s not including fission power, which is already economically efficient, or fusion power, which has passed break-even and may soon become economically feasible as well. Fusion power is only limited by the size of your reactor and your quantity of deuterium, and deuterium is found in ocean water (about 33 milligrams per liter), not to mention permeating all of outer space. If we can figure out how to fuse ordinary hydrogen, well now our fuel is literally the most abundant substance in the universe.

And what if we move beyond the Earth? What if we somehow captured not just the solar energy that hits the Earth, but the totality of solar energy that the Sun itself releases? That figure is about 1e31 joules per day, which is 1e27 kilowatt-hours per day, or seven trillion times as much energy as we currently consume. It is literally enough to annihilate entire planets, which the Sun would certainly do if you put a planet near enough to it. A theoretical construct to capture all this energy is called a Dyson Sphere, and the ability to construct one officially makes you a Type 2 Kardashev Civilization. (We currently stand at about Type 0.7. Building that worldwide solar network would raise us to Type 1.)

Can we actually capture all that energy with our current technology? Of course not. Indeed, we probably won’t have that technology for centuries if not millennia. But if your claim—as Mark Buchanan’s was—is about fundamental physical limits, then you should be talking about Dyson Spheres. If you’re not, then we are really talking about practical economic limits.

Are there practical economic limits to growth? Of course there are; indeed, they are what actually constrains growth in the real world. That’s why the US can’t grow above 2% and China won’t be growing at 7% much longer. (I am rather disturbed by the fact that many of the Chinese nationals I know don’t appreciate this; they seem to believe the propaganda that this rapid growth is something fundamentally better about the Chinese system, rather than the simple economic fact that it’s easier to grow rapidly when you are starting very small. I had a conversation with a man the other day who honestly seemed to think that Macau could sustain its 12% annual GDP growth—driven by gambling, no less! Zero real productivity!—into the indefinite future. Don’t get me wrong, I’m thrilled that China is growing so fast and lifting so many people out of poverty. But no remotely credible economist believes they can sustain this growth forever. The best-case scenario is to follow the pattern of Korea, rising from Third World to First World status in a few generations. Korea grew astonishingly fast from about 1950 to 1990, but now that they’ve made it, their growth rate is only 3%.)

There is also a reasonable argument to be made about the economic tradeoffs involved in fighting climate change and natural resource depletion. While the people of Brazil may like to have more firewood and space for farming, the fact is the rest of need that Amazon in order to breathe. While any given fisherman may be rational in the amount of fish he catches, worldwide we are running out of fish. And while we Americans may love our low gas prices (and become furious when they rise even slightly), the fact is, our oil subsidies are costing hundreds of billions of dollars and endangering millions of lives.

We may in fact have to bear some short-term cost in economic output in order to ensure long-term environmental sustainability (though to return to Krugman, that cost may be a lot less than many people think!). Economic growth does slow down as you reach high standards of living, and it may even continue to slow down as technology begins to reach diminishing returns (though this is much harder to forecast). So yes, in that sense there are limits to growth. But the really fundamental limits aren’t something we have to worry about for at least a thousand years. Right now, it’s just a question of good economic policy.