Causal Inference, Instrumental Variable.
the relation between Z and T seems to have evolved into a non-linear one. Simple regression: Regression is upward biased as we may see (coeff T = 4.4 and the real effect is still 3). For the Wald estimator, we get: Point Estimate: 8.09 CI: [-392.997, 409.766] This reveals an enormous variance,