Why Are Restroom Hand-Washing Signs By the Sinks?

All over America, restrooms for the public (for example, in restaurants or public parks) have signs warning and exhorting us that "Employees must wash hands before returning to work" or "Hand-washing stops the flu!" These are useful public-health messages. However, in almost every restroom I've been to, the sign stares at you from the mirror behind the sinks. What is the point of reminding the already hygiene-conscious to wash their hands?

But in the San Francisco airport a few days ago, I finally found a "Clean hands, good health!" sign at the restroom exit door. I don't know whether it ever caused someone to U-turn and head for the sinks, but at least it isn't carrying coals to Newcastle.

The Quants and the Airlines Versus the Public

Baggage fees are a small part of the misery of American air travel. There's also connecting flights, which, to paraphrase the Nuremberg judgment, contain within themselves the accumulated evil of the whole. For if air travel were pleasant, who would mind changing planes and spending more time in the system?

Instead, the airlines make us pay to avoid the extra hours --- giving airlines an incentive to make air travel less pleasant. But once in a while you can beat the system.

For a memorial service at short notice, I once had to fly with my 2-year-old daughter to New York (and throw away our return flight to Boston). The price of a nonstop, one-way flight from Phoenix, Arizona to Newark, New Jersey: $1200 (for two people).

But what if I flew slightly farther, allegedly changed planes in Newark, but just left the airport? So I went back to airline's website and asked for a one-way flight to Manchester, New Hampshire. It was only $400 (for two people). Not only did the flight connect in Newark, but the Phoenix--Newark leg was the same flight that cost $1200 nonstop!

We Once Had Self-Driving Cars

A frequent response to the dysfunctions of American air travel is technological: namely, self-driving cars (also see this article). In a self-driving car, you can relax, even sleep, while being driven safely to your destination at 60 mph. We once had such a system. It's called a train network.

Compared to air or car travel, a decent train network is cheaper, more environmentally friendly, and quicker. As an example, I'll compare two door-to-door, city-center-to-city-center journeys.

The Absurdity of U.S. Air Travel: Baggage Fees

On the way home from visiting my brother-in-law's family in Ohio, we changed planes in Chicago. To avoid the baggage fees, we, like most of our fellow passengers, schlepped our luggage through the airport to the gate in Dayton.  Of course, we had to gate-check it because the overhead bins were long-full by the time we could board (boarding group: infinity). The plane arrived in Chicago late, we waited 20 minutes for our baggage to be unloaded, and then we sprinted to (and barely caught) our connecting flight to Boston.  Naturally, we had to gate-check the luggage for that flight as well.

Baggage fees brought U.S. airlines in 2011 a total of $3.4 billion. That amount is almost one-half of the industry's 2011 profits of $7 billion. To double the airlines' profits, the social benefit of which is highly unclear, society incurs many costs:

Saving Boston's Long Wharf Park From Extinction

Have you visited the beautiful and historic Long Wharf Park on Boston Harbor? And what do you do when the government goes rogue?

The Boston Redevelopment Authority (BRA), in defiance of the Massachusetts Constitution, is trying to turn Long Wharf Park into a late-night restaurant and bar. The Massachusetts Constitution requires a two-thirds vote of the Legislature before public parkland can be converted to other uses. The vote has not happened, and the BRA is telling the world that it is unneeded. As featured in today's Boston Globe, ten local residents, including me, have been trying to force the government to obey the constitution.

A Tax Taxonomy

Dan Hamermesh’s much-discussed post about taxing capital gains brought to mind my own taxonomy of taxes, so to speak, from least to most progressive:

1. Poll tax. Everyone pays the same amount. What could be fairer than this?!
England tried it in the late 14th century, leading in 1381 to Wat Tyler's Rebellion. Six hundred years later, England tried it again, leading to the Poll Tax Riots.

2. Sales tax. Goods are taxed at a flat rate (often 17 to 20 percent in Europe, and 5 to 8 percent in various American jurisdictions). Because the wealthy spend a smaller fraction of their income on taxable goods than do the poor, this tax is less progressive than a flat income tax.

3. Flat income tax. Everyone pays the same fraction of his or her income. This tax was the core of Steve Forbes’s platform when he ran for president in 1996 and 2000.

Beware the Weasel Word "Statistical" in Statistical Significance!

As Justin Wolfers pointed out in his post on income inequality last week, the Census Bureau was talking statistical nonsense. I blame the whole idea of statistical significance. For its weasel adjective "statistical" concedes that the significance might not be the kind about which you care. Here, I'll explain what statistical significance is, and how its use is harmful to society.

To evaluate the statistical significance of an effect, you calculate the so-called p value; if the p value is small enough, the effect is declared statistically significant. For an example to illustrate the calculations, imagine that your two children Alice and Bob play 30 rounds of the card game "War," and that the results are 20-10 in favor of Bob. Was he cheating?

To calculate the p value, you need an assumption, called the null (or no-effect) hypothesis: here, that the game results are due to chance (i.e. no cheating). The p value is the probability of getting results at least as extreme as the actual results of 20-10. Here, the probability of Bob's winning at least 20 games is 0.049. (Try it out at Daniel Sloper’s "Cumulative Binomial Probability Calculator.")

Why My Favorite American Cities Have a Chinatown

Relatives from South Africa were visiting and we got to talking about which cities to visit in America. I shared my list: San Francisco, New York, Boston, Washington, DC, Seattle, and Philadelphia. Each city has a Chinatown. Coincidence? Or maybe the connection is just that I like Chinese food. Indeed, our family has been going to a favorite dim-sum restaurant most every week since moving to Boston seven years ago.

Then the larger connection came to me. Chinatowns were made by Chinese laborers building the railroads (when the laborers had finished this vast public-works program, the Chinese Exclusion Act barred most Chinese from emigration to or citizenship of the United States). Having a Chinatown marks a city as of the railroad era, built up before the wide deployment of the automobile. As Lewis Mumford said, "The right to have access to every building in the city by private motorcar in an age when everyone possesses such a vehicle is actually the right to destroy the city." Cities with Chinatowns had enough roots to escape carmageddon.

Division, Not Long Division

Division is the most powerful arithmetic operation. It makes comparisons. When the numerator and denominator have the same units, the comparison makes a dimensionless number, the only kind that the universe cares about. Long division, however, is something else entirely. In my post "Dump algebra," many commentators objected to my loathing of long division. But long division is not division! Long division is just one way to do the computation, and is far from the most useful way.

I'll illustrate with an actual example of division. For my environmental-protection lawsuit, now in the Massachusetts Supreme Court, I needed to divide 142,500 by 4655.

Obedience on the Job

On America's first subway, Boston's Green line, the middle doors stopped opening. When I asked the driver to open the doors, he said that he couldn't: now all boarding and deboarding at the above-ground stops is through the narrow front door by the fare box. Ah, the MBTA: making up for the 23 percent fare hikes on July 1 with improved service!

Me: "The new policy slows the ride for everyone. Now passengers cannot board and pay their fares until all the deboarding passengers have left."

Driver, shrugging: "It's the new policy. I just do what my boss tells me to do. I don't question."

Me: "We could use some questioning."

Driver: "Questioning isn't part of my job. I just wait for my pay day."