He believed that monopolizing the nature resources was helpful on improving the government income, with fewer complaints from the public than raising taxes. The strategy was described by himself to the Duke of Huan as "managing the mountain and the sea（官山海)", which mainly refers to iron mine from the mountain and salt from the sea. Under his policy, private business who produce salt by boiling seawater and iron by mining must sell all outputs to the government, and the government resell refined salt and iron products, with huge price gap, to all household in State of Qi.