Kernrechtsfrage
Whether the IV pension could be revised retroactively due to a failure to report higher earnings.
Extrahierter Entscheid
The insured breached the duty to report with at least negligence, so retroactive revision was lawful.
Extrahierte Begründung
The increase in occupational activity had not been reported to the IV office in time. The duty to notify is personal and not replaced by the employer's dealings with social security bodies.