7.1 Causation, Blame, and Policy

Distinguishing singular causation (A caused B) from general causation (X tends to cause Y).

The Lesson in Context

This course has so far only discussed general causation, which can be demonstrated through randomized controlled trials and to a weaker extent Hill's criteria. But personal, policy, and legal decisions often depend on singular causation as well. It also sometimes matters whether the causation is by commission or by omission. The famous Trolley dilemma is discussed.

6.1 Correlation and Causation

• RCTs only demonstrate general causation but not singular causation. Correlation is also a statistical relationship between two variables, rather than between two singular events.

6.2 Hill's Criteria

• As a substitute for RCTs, Hill's criteria also only demonstrate general causation, but can be used in some cases as partial evidence for singular causation (especially plausible mechanism and temporal sequence).

8.1 Orders of Understanding

• Any given effect is brought about by a complex combination of many causes (which may interact with each other), with varying degrees of influence on the outcome. This is true for both singular and general causation.

9.2 Biases

• The omission bias is one explanation for the status quo bias, in that humans tend to prefer not actively changing the current situation or trend, even when it may be worse than the potential pitfalls of the new outcome.

Takeaways

After this lesson, students should

1. Distinguish between singular and general causation.
2. Distinguish between the evidence needed to establish singular or general causation.
3. Identify different policy implications of singular or general causation.
4. Recognize cases where omission bias and status quo bias can influence decision making, even when this results in a worse outcome.

Singular Causation

A causal relation between two specific events; A caused B.

General Causation

A causal relation between two variables; X causes Y.

Omission Bias

Omission bias is the tendency to favor an act of omission (inaction) over one of commission (action).

Status Quo Bias

A preference for the maintenance of a current or previous state of affairs ("status quo" is Latin for "state in which"), or a preference to not undertake any action to change this current or previous state.

Drug Trials

A randomized controlled trial for a drug may demonstrate its general therapeutic effect (general causation), e.g. taking this drug reduces the risks of this disease, but it cannot conclusively demonstrate a causal connection in any particular instance of a patient taking this drug (singular causation).

---

Weather and Climate Change

One can claim that climate change causes extreme weather events (general causation), but not that any particular instance of wildfire was caused by climate change (singular causation).

This drug will absolutely cure you, because there was a really big RCT that showed it works for your exact disease!

RCTs can only establish singular causation.

Useful Resources

Discussion Slides Template

The discussion slides for this lesson.

Recommended Outline

During Class

5 Minutes	Introduce the lesson and go over the plan for the day. Make sure people have groups, spokespeople, etc.
35 Minutes	Guide the students through the singular and general causation discussion questions.
15 Minutes	Discuss the trolley problem example.
25 Minutes	Go through the life saving treatments discussion.

Lesson Content

Have students discuss the following questions in small groups. Each question and sub-question should take around five minutes.

1. Which kind of causation can an RCT establish?

General causation. The purpose of an RCT is to average away all the nuances that arise from the singular cases of the individuals in the trial.

2. Suppose we conduct an RCT that determines salt causes heart disease. Suppose Sally is in our study, has a high level of salt, and contracts heart disease. Did Sally's salt intake cause her heart disease?

It's impossible to say for sure. All we really know is that Sally was more likely to develop heart disease than someone with less salt intake. In this way the trial is suggestive that the salt intake played some role in causing her heart disease. But, that's all our trial tells us.

3. On January 4, 2022, a federal inquiry into the Dixie Fire of August 2021, the second largest wildfire in California history, determined the wildfire began when a tree came in contact with a power line operated by PG&E.
   1. Is this a statement of singular or general causation?
   2. It is well established that climate change increases the number and intensity of wildfires in California. Given this known fact, why did the federal investigation not immediately conclude that climate change was the cause?
   3. PG&E has faced criminal charges from multiple California counties for the role of its equipment in causing wildfires. When determining guilt or innocence, does the legal system typically focus on singular or general causation?
   4. Assume you're in charge of creating policy to prevent California wildfires like the Dixie Fire from happening in the future. What are some policies that might have prevented the Dixie Fire? Does policy making typically focus on singular or general causation?
4. Why do you think it is so tempting to assume that each event has a singular person or entity to blame? When is this useful or not useful?

Activity 1

[Brief description of and motivation for the activity]

[Common misconception or thing to look out for.]

[Thing you really need to look out for!]

[Title]

[Useful tip, guideline, or other background.]

Instructions

[n] Minutes	[Activity.]
[n] Minutes	[Activity.]

Discussion Questions

[Question 1]

[Possible misconception that may need to be corrected and clarified.]

[Intended answer to the above question.]

---

[Question 2]

[Possible misconception that may need to be corrected and clarified.]

[Intended answer to the above question.]

---

[[[Previous Lesson]|⟨]]

[[[Previous Lesson]|Previous]]

[[[Previous Lesson]]]

[[[Next Lesson]|⟩]]

[[[Next Lesson]|Next]]

[[[Next Lesson]]]