Let him know how fortunate he is with all the good things his has in America, while other children in China or Africal are straving.
I found that is the easiest way to get kids to be more compassionate, considerate and less self-centered.
Since I work in a big company with lots of Chinese, we got lots requests about supporting Chinese children and elementary Schools that are in dire needs.Looking that those pictures and reading those stories is just heart breaking. China has made great economical progress during the past 20 years and has become the driving froce for the consumption of the luxious goods around the world, and yet there are many Chinese children can only afford to have water for lunch, and study in schools with no lighting, broken tables and chairs and badly damaged houses. I let my kids read those stories and then get them to help me to pick the projects I donate every year.
Another charity activity I do every year is the Giving Tree during Xmas time. It is for the local people inneed, including children from low income families and senors with low income. I pick 4 of those request cards from office Xmas tree, and let my kids to the shopping and writing a card to the recipients.
These activities are really effective in keeping my kids grounded. My kids never made any reqests, toys/clothes/gadgets, I would consider improper. I rarely need to decipliine my kids and I've never had trouble in doing so.
