Quote from aeliodon:
The bottom line is that you are a complete idiot for 'investing' in an asset with a negative net yield. You're better off spending that money or trading it with leverage to earn a much higher return (assuming you know how to trade).
Its no surprise hedge funds, the derivatives, LBOs, etc. have been so hot recently - this is the smart money trying desperately to avoid the negative returns that the benchmark T-Bonds offer by taking on more risk.
You forget the price appreciation when yields drop to the bottom of the barrel (and when trading them before maturity).
On the other side they are safe instruments when holding to maturity (some assumptions hold of course).
Bottom line is, bonds make good sense in a diversified portfolio of, for example, weathly people. There is no negative yield, your computation is simply incorrect (look only at your double counting and also a US person is not exposed to currency fructuations when investing in US bonds (at least not directly). And foreign investors often hedge the currency risk or hold a view on its direction.
A lot of other flaws in your way of arguing as well....)