Arnold Kling

Too Complex and Interdependent

Arnold Kling, Great Questions of Economics
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There is no simple treatment that works in education or for economic growth. On education research, E.D. Hirsch, Jr. says,

If just one factor such as class size is being analyzed, then its relative contribution to student outcomes (which might be co-dependent on many other real-world factors) may not be revealed by even the most careful analysis...And if a whole host of factors are simultaneously evaluated as in “whole-school reform,” it is not just difficult but, despite the claims made for regression analysis, impossible to determine relative causality with confidence.

On economic growth, Jeff Madrick finds that there is no reliable relationship between tax rates and growth.

it seems that quite a few Americans, including economics writers and media hosts, think that low-tax countries unquestionably grow faster than high-tax economies. Right and left, they seem to attribute more rapid growth in America to lower taxes.

What may surprise them is that there is no evidence for that.

In my view, the causal factors in education and economic growth are too complex and interdependent to be studied easily. Here is a parable for a discussion question:

Imagine that you did not know how a lighting system for a room was designed. However, you are confronted with a control panel with 100 up-down switches in random positions. In fact, for the lights to go on, you need to have 8 switches in the "up" position and 7 switches in the "down" position. The other 85 switches do not matter. Moreover, unless all of the 15 critical switches are in the right position, no individual switch has any noticeable effect on the amount of light in the room. How would you go about figuring out how to turn on the lights?

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