<prompt> Translate the following text to EnglishVyanzo vitatu vya ukuaji wa kiuchumi katika mfano ni kuongezeka kwa uwekezaji wa kazi, mkusanyiko wa mtaji, na maendeleo ya jumla ya uzalishaji wa sababu.  <response>: The three sources of economic growth in the model are increased labor input, capital accumulation, and the advance of total factor productivity. 