Wednesday, September 30, 2009
Sunday, September 27, 2009
Most-Used Bible Verses
Ranges and Codomains
Friday, September 25, 2009
Phelps on Capitalism and Innovation
The issue of morality in economics is neither the fairness of income distribution nor the stability of financial systems. It is how human institutions can be shaped to correspond to human nature—to man’s nature as an innovator.... Prosperity and the development of the human spirit are linked in the dynamism of the economy. The dynamism of the American economy over the past two hundred years was strong, and that helps to explain why prosperity was high both in the sense of high employment and the sense of a high degree of personal satisfaction compared to that in other countries.... That is the positive moral content of economics—to realize an anthropology that starts with innovative human nature: homo innovaticus, not homo economicus. Existing economics has a negative moral content in that it treats economic factors as though they were pieces on a game board rather than human beings who learn, discover, and innovate. Politicians play the same game, channeling resources from one activity or social group to another without considering the effect on the creativity and judgment exercised within the economy and thus the deep rewards the economy imparts or fails to impart.... Even now, in the midst of an economic downturn, there are signs of vitality that weren’t present in the 1950s. There is exuberance, however irrational, in the banking system, and some originality here and there in hedge funds and private equity, and still some inventiveness in Silicon Valley. Although they may have caused more problems than they were worth, the exotic, new financial instruments showed that America is still the world’s leader in invention. They reflect America’s capacity to create. Unfortunately, the markets were unsophisticated and set mistaken asset prices.
Constructing a Risky Density Function
Thursday, September 24, 2009
Leo Strauss Audio File of Him Teaching Meno
Wednesday, September 23, 2009
Occupations over the Decades
Sunday, September 20, 2009
A New Word: Jobligation
Wednesday, September 16, 2009
Dynamic Pricing for Hockey Tickets
Similar to airline pricing, the best prices are often found early. Dynamic pricing will provide fans with great prices starting from the initial on-sale on Sept. 12. The upper level single-game ticket prices can go up or down based on a variety of factors, including league standings, opposing team, star players, day of the week, and real time supply and demand. Dynamic pricing for upper level tickets will continue all season. Fans will be able to check out the current prices at any time at DallasStars.com.
Tuesday, September 15, 2009
AJ refers me to Wikipedia's article on Cromwell's Rule:
Cromwell's rule, named by statistician Dennis Lindley, states that one should avoid using prior probabilities of 0 or 1, except when applied to statements that are logically true or false. (For instance, Lindley would allow us to say that \Pr(2+2 = 4) = 1.)
The reference is to Oliver Cromwell, who famously wrote to the synod of the Church of Scotland on August 5, 1650 saying
I beseech you, in the bowels of Christ, think it possible that you may be mistaken.
As Lindley puts it, if a coherent Bayesian attaches a prior probability of zero to the hypothesis that the Moon is made of green cheese, then even whole armies of astronauts coming back bearing green cheese cannot convince him.
This seems reasonable. But is there a psychological problem if we are sure of nothing in the world? We might be haunted by having to always to do a substantive Bayes's Rule calculation. Maybe not, though. The substance of Lindley's idea is the story of the astronauts bringing green cheese-- we will throw away our heuristic solid belief if that happens.
Saturday, September 5, 2009
The Blue-Eyed Islander Puzzle
Here is a well-known puzzle that I will probably be teaching next week. An island starts with 2 blue-eyed people and 48 green-eyed, but the people do not know these numbers. If a person ever decides his eyes are blue, he must leave the island at dawn the next day. There are no mirrors and people may not talk about eye color, but they see each others' faces.
What will happen? -- nobody leaves.
Now an outsider comes to the island and says, "At least one of you has blue eyes".
The next dawn, nobody leaves, but on the second dawn, both blue-eyed people leave.
The reason: Both blue-eyed people realize there are either 1 or 2 blue-eyed people. When nobody leaves on the first dawn, each realizes that there must be 2-- and he is one of them.
Labels: game theory