I have a completed novel which also deals with overpopulation, titled "We the People Are Good to Eat".
The plot summary states "In a fatally overpopulated future Earth, all that the people have to eat is each other, and they thank God for every meal.
In this world, keeping the population trimmed and the meat quota filled is every citizen’s responsibility. Gladiator type combat games are now a high school sport. This is the students’ way of participating in both the population trimming and meat harvest.
A Cheerleader-Warrior Girl discovers that certain things in this world are not the way that everybody believes. Then things begin to change."
I'm planning to begin posting the novel here, one chapter at a time, maybe beginning tomorrow. If you'd be interested in reading it, you might also be interested in working with me; seeing if we can revise the novel into a screenplay.