Mind Matters Natural and Artificial Intelligence News and Analysis

TagJames Tobin

Stock Market Management

Some Economic Models are Alluring, Others are Useful

In some markets, prices are affected by market forces and in others, like the job market, they are not

Statistician George Box is credited with the aphorism, “All models are wrong, but some are useful.” Unfortunately, as the brilliant economist Ed Leamer, once quipped, “Economists are like artists. They tend to fall in love with their models.” A large part of the art of economics is distinguishing between attractive models and useful models. The traditional bedrock of economics is the demand-and-supply model. Every introductory economics course explains how demand and supply are related to price and how the equilibrium price is where demand is equal to supply. This can be a very useful model for predicting how changes in demand and supply affect prices and trades — if we make the tempting assumption that the market price is equal…

Worried doctors and medical researchers on conference meeting, discussing possible solutions for resolving a world health crisis. Health and medical care concept. Selective focus.

Computers Excel at Finding Temporary Patterns

Which contributes to the replication crisis in science

The scientific method calls for the rigorous testing of plausible theories, ideally through randomized controlled trials. For example, a study of a COVID-19 vaccine might give the vaccine to 10,000 randomly selected people and a placebo to another 10,000, and compare the infection rates for the two groups. If the difference in the infection rates is too improbable to be explained by chance, then the difference is deemed statistically significant. How improbable? In the 1920s, the great British statistician, Sir Ronald Fisher , said that he favored a 5 percent threshold. So 5 percent became the Holy Grail. Unfortunately, the establishment of a 5 percent hurdle for statistical significance has had the perverse effect of encouraging researchers to do whatever…