Ever read Brave New World? Kinda like that. Most of the population kept doped up and happy; western governments are almost there with "reality television", but I think they'll need a little chemical nudge to complete the process, and cancel out any of the "news" or "politics" nonsense that may slip through. Most efficient distribution method would probably be via the water system, but methods to deal with anyone who uses well water or buys bottled water will have to be found; probably could just spike the bottled water supplies first, then the general supply, since everyone knows that people who drink bottled water are loopy anyways, so no one will notice. Once this is accomplished, the time to begin labor restructuring begins. First, round up everyone with a useless job in regional processing camps. All politicians, lawyers, business executives, "celebreties", telemarketers, journalists, writers, and artists will be rounded up, given a few extra hits of the happy drug, and sent to the camps. Those that are deemed capable of doing real manual labor are then assigned to new jobs in agricultural, janitorial, construction, etc., and others are sent off to help make even more reality television. Everyone else will be shifted into the areas in and around major cities. To facilitate the move for those too attached to "home" for the happy drug to overcome, there should be some kind of plague where the cure can only be had at the major cities; once you come into the city though, you can never leave. Brave New World has genetic classes of people; I think this is too hard. Instead, we'll just pump the unhappy ones with so much of the happy drug, that they will soon become so baked that even if they're sober, they will be incapable of thought. The stratification will then occur naturally. Once everyone is kept within a certain area, individual vehicles will become unnecessary except for the few in addition to myself who run the show. You can walk to anything you need, and can take public transit if you want to go elsewhere. Ixnay on the asgay, no oil problem. Also, once everyone is in a confined place, it will be easier to implement population control measures; six billion is far too many, but I could get it down to a more managable two billion in a few generations by throttling back the birth rate and eliminating any who can no longer provide any value to the doped up society. If a reality television star loses popularity, the only humane thing to do is make them OD. Same with elderly, disabled, and terminally ill. So, within about 30 years, birth rates can be brought back up to stabalize the population at around 2 billion.
Or not
