'Economism' is one of the tendencies combatted in the early phase of the Cultural Revolution. 'Economism' simply means that economical factors have priority over political and ideological factors, an idea opposed by Mao and his supporters.
Text on the armband: 造反队 (Rebel team, Zaofan dui).
Text on the paper the man is tearing: 经济主义 福利主义 (Economism Welfarism - Jingji zhuyi Fuli zhuyi).