.
  - Only how much it changes in response to a change in `\(x_{0i}\)`.

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# Diff 2. Whether selection bias matters.

`$$\color{#6A5ACD}{Y_i} = f(x_{0i}, x_{1i}, ..., x_{Ni}) = \color{#e64173}{\beta_0} x_{0i} + \beta_1 x_{1i} + \beta_2 x_{2i} + ... + \varepsilon_i$$`

.hi-turquoise[**Description:**] **No.** Only want to infer patterns from observed data.
- The reasons why patterns exist is an entirely separate question.

.hi-purple[**Prediction:**] **No.** Only want to infer patterns from observed data. S