Shirley Jackson's The Lottery

This seemed very familiar to me when i read this. I had seen the hunger games movie which has a similiar plot but different scenario. They foreshadow the picking up of the stones by the children. I guess i did not catch that when i was reading it. The ending kinda threw me for a loop. I did not understand why they had to stone to death someone. I wish there was more back round into whty they did the lottery.