I know that due to early effect in a npn transistor the effective base width reduces.However I can't understand how this will lead to an increase in emitter current. Some sources say that the charge concentration gradient increases due to this early effect and hence the increase in emitter current but how can the charge gradient increase since that is determined by doping. Other sources claim that this early effect will reduce the base current leading to increase in collector current which therefore means that the emitter current increases, this i think is wrong as everyone here knows. Can any one please explain it then. Any help will be appreciated Thank you.