effectiveness - the ability to produce the result that is intended - ประสิทธิผล Articles found: Night-time economy needs a boost (25/10/2021) New anti-Covid phone app tracks shoppers (14/05/2020) More Phuket virus fears; no Bangkok mall trial (11/05/2020) The stuff that dreams are made of (20/01/2018) Get ready to spend: Shopping tax break begins Nov 11 (08/11/2017)