There are a number of themes underlying this taut, thoughtful, enjoyable novella.
In the absence of strong parental authority, teenagers will run wild in gangs - if only for the purpose of self-protection and a taste of freedom. Not just in the confines of Lunghua camp, the streets of Rio or the poorer areas of London (think London Fields Crew, the Hoxton Boys, the Shakespeare gang of Stoke Newington or the E5th Ridaz of Lower Clapham, Hackney) but, potentially in affluent, isolated, gated communities too. It's the nature of the beast rather than the state of the environment.
We all need a certain amount of risk to feel fully alive. If all risk is removed from life (as in the lives of the teenagers in this novella) then we will seek it elsewhere.
When seat-belts became compulsory, people drove faster and took up bungee-jumping. Meanwhile, the Baby On Board generation has turned to tombstoning or (in some cases) decided to become a shahid for their kicks.
We have been warned.