How to identify causality, stability and ROC from the pole-zero plot?

1. How do you find the causality of a pole zero plot?
2. How can you tell stability from pole zero plot?

How do you find the causality of a pole zero plot?

If the ROC extends outward from the pole with the largest (but not infinite) magnitude, then the system has a right-sided impulse response. If the ROC extends outward from the pole with the largest magnitude and there is no pole at infinity, then the system is causal.

How can you tell stability from pole zero plot?

If all the poles lie in the left half of the s-plane, then the system is stable. If the system has two or more poles in the same location on the imaginary axis, then the system is unstable. If the system has one or more non-repeated poles on the imaginary axis, then the system is marginally stable.