February 27, 2019

Causal Claims

Plan for Today:

(1) Deterministic Causal Claims

Review:

  • necessary conditions
  • sufficient conditions
  • conjunctural causation

New:

  • multiple causation

(2) Probabilistic Causal Claims

Deterministic Causal Claims

Necessary/Sufficient Conditions

necessary conditions

A claim that there is some cause \(C\) without which the effect cannot occur

  • If not \(C\) then not \(E\)

sufficient conditions

A claim that there is a cause \(C\) that, on its own, always produces effect \(E\)

  • If \(C\) then \(E\)

Things are usually more complicated

Conjunctural Causation:

conjunctural causation:

When an effect \(E\) depends on a combination of causes \((C_1, C_2, \ldots, C_k)\)

This can take two forms:

  1. Multiple necessary conditions

Effect \(E\) only happens when some combination of causes \(C_1, C_2\) is present

  • If not \(C_1\) and \(C_2\), then not \(E\).

Conjunctural Causation:

  1. Conditional Effects

Effect \(E\) of cause \(C_1\) differs depending on some other factor \(C_2\)

  • If \(C_1\) and not \(C_2\), then \(E_1\); If \(C_1\) and \(C_2\), then \(E_2\)
  • Exposure to Nazi Radio Propaganda (in 1930s) caused
    • increase in anti-Semitic violence in communities with history of pogroms
    • decrease in anti-Semitic violence in communities with no history of pogroms

Multiple Causation:

multiple causation:

Claim that more than one sufficient causes or set of causes (\(C_1, C_2, \ldots C_k\)) can produced the same effect \(E\)

  • \(C_1 \to E\) OR \(C_2 \to E\)
  • conjunctural causation also involves multiple causes, but the logic is different:
    • \(NOT \ (C_1 \ and \ C_2) \to NOT \ E\) (multiple necessary conditions)

Multiple Causation: Example

What causes a rise in anti-immigration sentiment?

Rise in anti-immigration sentiment caused by:

  • Terrorist attack/major crime perpetrated by a non-citizen

or

  • Increase in unemployment/competition for jobs

or

  • Increase in popularity of ethno-nationalist ideology

Each of these is a sufficient cause, so it is multiple causation

What is this, though?

What causes a building to burn?

A building will burn when:

  • The \((A)\) the building has a wood frame and \((B)\) there is a short circuit in electrical wiring

OR

  • In the building there is \((C)\) a can of gasoline that is next to \((D)\) a furnace with an ignition

Multiple causation? Conjunctural causation?

Multiple and Conjunctural Causation

It is both

Multiple sufficient conditions for a building to burn; each sufficient condition has multiple necessary conditions

  1. \((A)\) wood frame and \((B)\) short circuit

  2. \((C)\) gas can and \((D)\) furnace

This very common in reality

Multiple and Conjunctural

Why do civil wars happen?

  • \(C_1\): ethnic diversity AND \(C_2\): political inequality between groups (e.g., Sri Lanka; Kurds in Turkey)

OR

  • \(C_3\): interference by foreign governments AND \(C_4\): left-right ideological polarization (e.g., Nicaragua; Spain)

INUS Conditions

You will not be assessed on this (but it might be helpful)

Because causality can be complex, we say that: Something is a cause \(C\) of effect \(E\) if

\(C\) is [I]nsufficient but [N]ecessary part of a condition which is itself [U]nnecessary but exclusively [S]ufficient for the effect \(E\)

Example: Wood frame is a cause of building fire, because

  1. \((A)\) Wood frame and \((B)\) short circuit is [S]ufficient for fire.
  2. \((A)\) and \((B)\) [U]nnecessary for fire (b/c there are other ways).
  3. \((A)\) Wood is [N]ecessary for \((B)\) short circuit to produce fire.
  4. \((A)\) Wood by itself is [I]nsufficient to produce fire.

Deterministic Causal Claims

When we seek to investigate causes of effects (we focus on an effect and attribute causes that produce it)…

in principle, there is a list of all conditions (conjunctural or otherwise) under which effect will always or never occur

  • e.g. a list of all combinations of conditions that can create the effect of a building burning.
  • such a list would let you determine exactly when effect occurs vs not.

Deterministic Causal Claims

When we seek to investigate effects of causes (we reverse focus and look at causes and what effects they produce),

does it make sense to speak deterministically?

e.g., does it make sense to claim:

  • "Wood framing causes buildings to burn down (every time)?"
  • "Short circuits cause buildings to burn down (every time)?"
  • "Presence of indoor gas furnaces cause buildings to burn down (every time)?"

Interlude: Coin flips:

Interlude: Coin flips: