Aresearcher finds a that people who own more than two cars have bigger homes, more garage space and make more money than people who own one or two cars. her inference that having more than two cars causes people to have homes with bigger garages is lacking which type of causal evidence? 1. economic instability 2. temporal precedence 3. covariation of cause and effect 4. elimination of alternative explanations

The correct answer is 4.

Explanation:

According to Cook and Campbell's Experimental and Quasi-Experimental Designs for Generalized Causal Inference (2002), in order to establish a valid cause-effect correlation, three conditions must be met:

- Temporal precedence: the cause must occur before the effect.

- Covariation of cause and effect: changes in the cause must cause a change in the effect - they're linked together.

- Elimination of alternative explanations: the cause must be the explanation for the effect.

The researcher in the question has established a cause-effect relationship between owning two cars (cause) and having a home with a bigger garage (effect). However, she hasn't eliminated alternative explanations, like a people with a larger income owning a larger house and more cars, or even inverting the cause-effect relationship. Thus, her affirmation lacking causal evidence.