Inflation forces are backing off in Australia.The Import Price Index fell 1.6 per cent in the September 2017 quarter, the ABS said yesterday. This follows a fall in the June 2017 quarter of 0.1 per cent.The Export Price Index fell 3.0 per cent in the September 2017 quarter. This follows a fall in the June quarter of 5.7 per cent.Among imports, prices of office and automatic data processing machines fell 4.7 per cent.  Telecommunication and sound recording equipment prices fell 7.8 per cent.The fall in export prices is unsettling for mercantilists.Prices for coal, coke and briquettes sank 7.4 per cent over the quarter. Prices for ores and metal scrap fell 1.5 per cent, while those for gas, natural and manufactured, fell a neat four per cent.Through the year to September 2017, the Export Price Index rose 14.2 per cent, driven by Coal, coke and briquettes.Through the year to September 2017, the Import Price Index fell 0.4 per cent, driven by telecommunications and sound recording equipment.The appreciation of the Australian dollar against the United States dollar had a downward effect on import and export prices in the September quarter 2017, the ABS said.