I wrote this post over the weekend but given Paul Samuelson's classic contribution to public goods theory and to economic textbooks it seems to also fit today.

In Modern Principles we use asteroid deflection as our example of a public good. Aside from memorability, the example has two virtues as a teaching tool. First, asteroid deflection is a true public good for all of humanity which raises free riding issues on a worldwide scale. Second, asteroid deflection is an example of a public good that is currently provided neither by the market nor by government. Thus the example underlines the fact that public goods are defined by their characteristics–nonexcludability and nonrivalry–and not by whether they are publicly provided, a point of confusion for many students.

The example may seem fanciful but Tyler and I are quite serious about the

importance of asteroid deflection. Large asteroid hits are rare but if

a large asteroid does hit, billions will be killed. As a result, sober calculations suggest that the lifetime risk of dying from an asteroid strike is about the same as the risk of dying in a commercial airplane crash. Yet we spend far less on avoiding the former risk than the latter.

A new report from the National Academy of Sciences discusses efforts to detect near earth objects (NEOs). Progress is mixed:

The United States is currently the only country with an active, government-sponsored effort to

detect and track potentially hazardous near-Earth objects (NEOs)…

Congress has mandated that NASA detect and track 90 percent of NEOs that are 1 kilometer in diameter

or larger. These objects represent a great potential hazard to life on Earth and could cause global

destruction. NASA is close to accomplishing this goal. Congress has more recently mandated that by

2020 NASA should detect and track 90 percent of NEOs that are 140 meters in diameter or larger, a

category of objects that is generally recognized to represent a very significant threat to life on Earth if

they strike in or near urban areas….The administration has not requested and Congress has not

appropriated new funds to meet this objective….[Thus] the current near-Earth object surveys cannot meet the goals of the 2005 NASA

Authorization Act…

Moreover, detection is only the first step towards deflection.

As a classroom discussion starter I like the video embedded below. The jovial attitude of the announcers contrasts amusingly with the topic while subtly illustrating some of our biases in perception yet the video does cover the main points about the worldwide risk, the fact that asteroid deflection is a public good and it hints at the free rider problem. I do doubt the bit about the riches available from asteroid mining. Enjoy.