What do people mean when they talk about the 'birth lottery'?

Those born in developed nations tend to have better life outcomes than those born in developing nations. That's what's referred to when people talk about the "birth lottery". 

"The lottery of birth is a philosophical argument which states that since no one chooses the circumstances into which they are born, people should not be held responsible for them (being rich, being poor and so on).

The lottery of birth argument has been used by philosophers such as John Locke, Thomas Hobbes and Jean-Jacques Rousseau, but more modern day uses have been prompted by political theorists such as John Rawls, who explores the subject in depth in his book A Theory of Justice." 

When we die we are just removed from the current body, and returned to another host body to start all over again.  With no memory of the past life (exceptions)Not (apparently) knowing if the new life will be worse, the same, or better. Odds would say worse.  Whether or not a G*D figures into it is unknownFor those who need it. We do have Heaven, Hell, and purgatory right here on earth, when you look around. Sometimes all within the same life. So there is no need to for a Spiritual existence.Life is eternal.  

And are you pretending today that you don't actually know what that phrase refers to? I only ask because you post here quite a bit, and typically it's dishonest trolling (forgive the redundancy), that you engage in.