I am not assuming any absolutes. Gold just currently happens to be a marketable commodity with a long history of stability—far more so than promises of labor. O

I am not assuming any absolutes. Gold just currently happens to be a marketable commodity with a long history of stability—far more so than promises of labor. Obviously that could change. If you don't care for gold, substitute any other marketable commodity. Gold could lose all value if everyone, including the owner, stopped demanding it, including for industrial use and jewelry. There is no precedent for such an event but it is indeed a possibility. A promise of labor, on the other hand, can lose all value if just one particular person chooses to renege on the agreement or is rendered unable to fulfill the IOU. That sort of thing happens all the time.