When you rule the world, what kind of economy would you have?
I've actually given this some thought. As we've seen, pure capitalism results in widespread poverty. Unfortunately, humans can't actually do true communism. At least not as I understand it. Besides, that wouldn't let me live in the lavish opulence I deserve. (just kidding! maybe.)
As a benevolent but iron-fisted dictator, I would have to control all essential human needs: water, power, food, shelter, internet access, things like that.
In order to provide everybody with at least decent quality of living, a certain level of basic necessities would be provided to every citizen: a small living space, healthcare, nutritious food rations, power, internet access, and other things I can't think of off the top of my head.
For more extravagant things, such as larger homes, luxury foods, non-medical-necessity massage, etc., you would have to pay out of pocket. These would not be government controlled businesses--these would be privately owned, allowing citizens to own, operate, or work for a nongovernmental enterprise for their own monetary gain.
Farmers, power technicians, and any other profession relevant to a basic human need would have a government-controlled provider, though private providers would not be forbidden. It's simply that you would have to purchase the farmland to set up a farm, or build a generator to provide power. It can also be hard to compete with a provider that doesn't operate at a large profit margin.
Taxes would, of course, support things like free healthcare and basic housing. Sales tax, property tax on non-basic housing, a portion of interest on loans, everything would send something back to the government, which would then be paid back out in the form of free healthcare, basic housing, pay for government employees, etc.
I'm not an economist, but the basic goal of the system is to combine a government that helps every citizen with a system that allows people to innovate and make their own fortune.
In addition, any citizen with an idea for a more efficient method may petition the government for a grant to create a proof-of-concept and/or half ownership in the endeavor. Should the citizen succeed, the government adopts the new method and employs the citizen, or allows the citizen to privatize and compete with the government (who still has about half-ownership, a silent partner that collects a portion of the profits) for customers, depending on circumstance. For example, a new breakthrough in healthcare would have to be sold to the government for a lump sum or ongoing stipend, and possibly a job offer as a government sponsored researcher; a new type of car engine, however, could be allowed to compete with other privately owned automotive designers and manufacturers.
I haven't quite worked out how to deal with artists and writers without it seeming like government propaganda, but at least they will always have housing, food, power, and internet while they do their thing. Possibly bringing the patronage system back; having wealthy citizens and government officials support individual writers/artists so they can continue their work? Maybe anonymously, so that nobody accuses the government of having favorites. I'll figure it out.
I can't think of anything else right now, but I'm sure I'm leaving something out. And I'm also sure that the system I'm outlined has many flaws and a bit of an authoritarian approach, but the only authority I've ever really trusted was me. But that's what my army of economists will be there for: to make it work. Somehow.
And if anybody can point out flaws in the system, feel free to let me know so that I can refine it before I take power. The transition should go much more smoothly if the systems are fully ready to be implemented.