What is the difference between anchoring bias and availability bias?

Although anchoring bias and availability bias are both types of cognitive bias (or heuristics) and may seem similar, they are quite different:

• The availability bias refers to people’s tendency to estimate the probability of an outcome (e.g., being struck by lightning), based on how easily they can recall similar events. Because of this, people sometimes mix up ease of recall with probability or frequency and end up believing that some events are far more common than they actually are.
• Anchoring bias refers to people’s tendency to give disproportionate weight to the first piece of information they receive in a decision-making context. As a result, this becomes a reference point or anchor that influences people’s perception of subsequent information.

In other words, although both anchoring and availability bias influence our perception, anchoring is related to the order in which we receive the information, while availability is related to ease of recall.