Linked Questions

2
votes
2answers
724 views

Causality VS Correlation [duplicate]

When I have read this article 'http://www.analyticsvidhya.com/blog/2015/06/establish-causality-events/?utm_source=FBPage&utm_medium=Social&utm_campaign=150725' i still don't understand the ...
0
votes
1answer
3k views

Are two variables that are dependent also correlated? / Can two dependent variables not be correlated? [duplicate]

I cannot find the answer to my question anywhere, I hope someone can help. I did a Chi-Square test with several variables to see if they were dependent or independent. The result showed that they ...
1
vote
0answers
52 views

If a study indicates no correlation between two variables, does it also indicate a lack of casual relationship? [duplicate]

Of course, correlation does not equal causation. But I am having trouble understanding if there is no correlation between two variables, would this indicate a lack of casual relationship between them ...
1
vote
0answers
51 views

Is correlation required condition for causation? [duplicate]

We all know that Correlation does not imply causation, but I am wondering whether there can be causation without correlation. If there are such cases, could you explain them? I am asking this ...
75
votes
6answers
12k views

Does no correlation imply no causality?

I know that correlation does not imply causality but does an absence of correlation imply absence of causality?
40
votes
3answers
5k views

Does statistical independence mean lack of causation?

Two random variables A and B are statistically independent. That means that in the DAG of the process: $(A {\perp\!\!\!\perp} B)$ and of course $P(A|B)=P(A)$. But does that also mean that there's no ...
19
votes
5answers
2k views

What is effect size… and why is it even useful?

I have an introductory-graduate-level statistics background (assume I know mathematical statistics and probability at an undergraduate level (e.g., Wackerly et al., Ross' Probability), and have some ...
9
votes
4answers
2k views

Mathematical definition of causality

Let $Y$ and $X$ be random variables. $E(Y|X)$ is the conditional mean of $Y$ given $X$. We say $Y$ is not causally related to $X$ if $E(Y|X)$ does not depend on $X$, which implies it is equal to $E(Y)$...
16
votes
2answers
3k views

Difference between rungs two and three in the Ladder of Causation

In Judea Pearl's "Book of Why" he talks about what he calls the Ladder of Causation, which is essentially a hierarchy comprised of different levels of causal reasoning. The lowest is concerned with ...
12
votes
3answers
2k views

Is the linearity assumption in linear regression merely a definition of $\epsilon$?

I am revising linear regression. The textbook by Greene states: Now, of course there will be other assumptions on the linear regression model, such as $E(\epsilon|X)=0$. This assumption ...
6
votes
2answers
761 views

Simulating data - correlation vs causation

I'm just dipping my toe into correlation vs causation, so forgive me if I butcher some of the concepts here. To get a better understanding of these concepts from data, I would like to simulate data ...
4
votes
2answers
2k views

Independence vs Autocorrelation

In Section 3.2 of R. S. Tsay, Analysis of Financial Time Series, I read: The basic idea behind volatility study is that the series {r_t} is either serially uncorrelated or with minor lower order ...
4
votes
2answers
387 views

Suppose that $R^2=0$ . Does this imply that Y and X are unrelated? [duplicate]

Possible Duplicate: Under what conditions does correlation imply causation? Can somebody illustrate how there can be dependence and zero covariance? Or could there still be a relationship? Is ...
6
votes
2answers
896 views

How to report general precision in estimating correlations within a context of justifying sample size?

I have a study with 130 participants where most of my analyses involve examining the relative size of correlations between various psychological variables. I'm trying to comply with recommendations ...
2
votes
2answers
2k views

Comparing two sets of data over time to infer correlation or imply causation

I have two data sets, over a period of time that I would like to compare. I am very unfamiliar with statistics so sorry if this is simple. I need to use SPSS. I am comparing the number of journal ...

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