<prompt> Translate the following text to EnglishMfano wa Thres ni kwamba ikiwa discount inabaki bila kubadilika, na hivyo kubadilisha hauruhusiwi, elasticity ya kiasi cha msingi ni -0.189 na ya kiasi cha kazi ni -0.289.  <response>: The Thress model suggests that if the discount remains unchanged, and thus that shifting is not allowed, the elasticity of basic volume is negative 0.189 and of workshared volume is negative 0.289. 