This is not strictly a physics question, I just figured this is the best place to ask it. I think everyone is familiar with the subtle difference in the effects of gravity from the poles to the equator. At or near the equator, objects weigh about 0.5% less than they do at or near the poles. My question is, how come this doesn't cause any problems in trade? Let me explain: say you run a company based on the Netherlands or Sweden or some place similar and another company based in some country near the equator orders 10kg of something precious, say gold. You weigh it precisely, but when it is shipped to whomever ordered it, guess what he will tell you: "Look, you a-holes, I ordered precisely 10kg, but received 9.95kg instead, are you trying to scam me?". I guess that if I owned a big business I would be bummed to know that I consistently lose 0.5% of my earnings in that manner! How come there exist no such problems?