Unit 12 – Causality and bivariate causal hypotheses
Synonyms dependent/independent:
Independent variable - Dependent variable
Cause - Effect/consequence
X-variable - Y-variable
Exogenous concept - Endogenous concept
Treatment - Observation
Causality and explanation:
Types of questions:
1. Why did YOU become an alcoholic? (Asking for reasons)
- There is asked for a story, parts of this story could be checked
- Can be a starting point for more general ‘theories’
2. Why did THIS PERSON become an alcoholic? (Suppose the person died)
- Answering using existing knowledge about the case.
- Using causal hypotheses to offer an explanation
- Does not improve our general knowledge about causes
3. Why do PEOPLE Become alcoholics? (general)
- Testing a relationship between a cause and consequence .
Three aspects of causality:
1. Correct time order:
- The independent variable (X) precedes the dependent variable (Y) in time
o Example: The effect of alcohol acceptance during childhood and current
drinking behaviour
2. Association or correlation:
- X and Y are correlated
- If there is no correlation, there is no causality.
o Example: If alcohol acceptance during childhood is equal among alcoholics
and non-alcoholics
3. Non spuriousness:
- No third variable accounting for the association
o Example: Testing family circumstances and alcoholic, but not testing the
genes.
Time order problems:
- Measuring both variables at the same time may produce reverse causation.
Example: does a happy childhood make you more happy now?
- Collect data at different points in time to check time order.
Interrupted time series design= testing a variable before treatment and testing a variable
after treatment.
The effect of third variables /non-spuriousness/ modifier variable:
Relationships can be ‘spurious’ or seriously biased because of:
- Cofounding /explanation
- Interaction / specification / modification
Confounding/explanation=
- when a test variable is introduced, the relation between two variables gets weaker or
disappears. This variable explains the dependent and independent variable.
, - There is no relationship between variables, but the third variable makes it look like
there is a relation.
Interaction/ specification /modification=
- When a test variable is introduced, the relationship becomes weaker or disappears
for one of the variables but is maintained or gets stronger for the other variable.
Bivariate associations: positive or negative relations are also called the ‘sign’ of the
relationship.
- A basis for comparison (variables)
Deterministic and probabilistic relations:
Deterministic: if…. happens, then ‘’always’’ (not possible in empirical research)
Probabilistic: if…. happens, then ‘’relatively more/less often’’
Why probabilistic only?
- Measurement error impossible to measure perfectly
- Parsimonious models: simple models, omitted variables leaving weird variables out
because we want the world to be simple.
Testing hypotheses:
- Only if the expected relationship is deterministic, we can reject the expectation with a
single observation
- In the social sciences, all expected relationships are never deterministic. They are
always probabilistic
- This is partly because of the theory: there are always other variables affecting the
dependent variable too.
Testing a causal relationship by studying/testing/finding variation:
- Within (single) case analysis: (under these circumstances….)
- Between (across) case analysis: (compare people)
- Combined within
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller lynnpos. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $8.63. You're not tied to anything after your purchase.