All Questions
6
questions
0
votes
1
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28
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How to rewrite a multivariate polynomial term without redundancies?
This is from an exercise found here on page 60. My question is: what is meant by $\sum\limits_{i_1=1}^D\sum\limits_{i_2=1}^{i_1}...\sum\limits_{i_M=1}^{i_{M-1}}w_{i_1i_2...i_M}x_{i_1}x_{i_2}...x_{i_M}$...
1
vote
1
answer
266
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2 approaches for Monte-Carlo : weighted sum of $\chi^2$ distribution and Moschopoulos distribution with Gamma distribution
If I take as definition of $a_{lm}$ following a normal distribution with mean equal to zero and $C_\ell=\langle a_{lm}^2 \rangle=\text{Var}(a_{lm})$, and if I have a sum of $\chi^2$, can I write the 2 ...
user226073
2
votes
1
answer
61
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Summation notation
I am reading a statistics book which says:
" If $ X \sim N ( \mu, \sigma^2)$, it is verified that:
$ \sum_{i=1}^{n}X \sim N ( n\mu, n\sigma^2) $
My doubt is if it should have been written as $ ...
- 439
8
votes
1
answer
385
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Front-Door Adjustment formula: confusing notation
Pearl et al. "Causal Inference in Statistics: A Primer" (2016) p. 69 Theorem 3.4.1 provides the Front-Door Adjustment formula:
$$
P(y | \text{do}(X = x)) = \sum_z P(z | x) \sum_{x'} P(y|x', z)P(x').
$$...
- 68.6k
2
votes
1
answer
3k
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Notation for leads and lags in difference-in-differences
I was hoping someone could help clarify a notational discrepancy.
For example, Lord Pischke uses the following sigma notation in two different lecture notes published on the web, yet refers to the ...
- 6,244
1
vote
0
answers
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Dot subscript summation notation used in design of experiments
Context
I couldn't find a clear explanation of this on this site, and
thought that it might be of use. I have provided part of the answer, which
anyone is welcome to build from. I'm not sure how to ...
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