Types of efficiency

Allocative efficiency (definition and when it occurs)

Optimal distribution of resources, when Price/AR = MC

Productive efficiency (definition and when it occurs)

When output is maximised and cost is minimised, lowest point on AC curve / any point of PPF (Full exploitation of economies of scale)

X - inefficiency (definition and when it occurs)

when a firm lacks the incentive to control costs so there is waste of resources (e.g. monopolies), at any point on the AC curve

Dynamic efficiency (definition and when it occurs)

productive efficiency of a firm in the long run, when a firm re-invests profits to keep being efficient, any point on LRAC

Static Efficiency (definition and when it occurs)

Occurs in the SR, when a firm is either productively or allocatively efficient