[Jack Simth]

The anti-trust laws were made for a reason.

When a company successfully kills all large competitors, especially in a fairly necessary industry (fuel, building materials, food, et cetera), it can do things that can't be done otherwise.

A small company underselling you? No problem; they're still small, with a limited distribution area. Sell at a loss in that area until your opponent goes under, then raise prices back up to wherever you feel like it. Revenues from elsewhere will cover the shortfall, which will be fairly short-term, and in return, you maintain an effective monopoly.

Getting tired of doing the above every three years? Have a chat with all your suppliers / business customers, and arrange for exclusive contracts. They don't sell to / buy from anyone else. Your currently small competition can't sell to your customers and can't buy supplies. Shortly thereafter, they go under - no reaction required.

Want to be un-boycottable? No problem. Either of the above pretty much eliminates all competition; they don't buy from you, they go without. Try making a skyscraper without steel or concrete. Workers striking? Pity most of their skills aren't useful anywhere else. They're stuck with whatever wages you say. Quality sucks? Long as you can avoid lawsuits over the quality of your materials (e.g., it's not up to the specs you said it was, causing the bridge to fall - simple fix, if you're the only business; get it in writing that they won't hold you accountable for such things), they can't do a thing about it, as there's nowhere else to turn.

And of course, once you've integrated horizontally (all of that stage of the business - refining ore into steel, say) you can integrate vertically quite easily (for the previous example, that would be mining the ore, fabricating the beams, et cetera) and eliminate competition at other layers simply by not buying from them / selling to them at much higher prices.

THESE HAPPENED. That's why there's laws that supposedly stop such tactics in place in the US. They don't always seem to be enforced (RIAA and TicketMaster come to mind), but they're in place. Slight trouble with Big Oil, though, it's international. Federal law can't control what they do on the other side of the pond, and having the UN take such steps would be ... too scary.