According to Consumer Price Survey Result that 82 cities in Indonesian on September 2018, indicate that 16 cities was inflation and 66 cities was deflation. The highest inflation rate was happen in Bengkulu amount of 0,59 percent and the lowest in Bungo amount of 0,01 percent while the highest deflation rate was happen in Pare-Pare amount of 1,59 percent and the lowest in Samarinda amount of 0,01 percent, Mamuju ranks occupy on 30th lowest from 66 cities that was happen deflation.
Deflation in Mamuju City on September 2018 was happen because decreased of price at three expenditure group there are food group 1,86 percent; education, recreation and sport 0,01 percent; transport, communication, and financial services 0,20 percent; while group that had inflation was prepared food, beverage, cigarette and tobacco group 0,34 percent; housing, water, electricity, and fuel gas group 0,45 percent. While clothing and health expenditure group relatively stable.
The rate of index change of calender year on September 2018 in Mamuju was inflation 1,38 percent while change of index year by year (September 2018 to September 2017) was inflation 1,95 percent.