CAP RATE的算法， 和利息是毫无关系的。
CAP = NOI（before debt service）/ market value
同样， market value = NOI（before debt service) / CAP.
注意， before debt service, so it has nothing to do with interest rate.
房租涨， 就是涨 NOI， 空置高， 就是减少 NOI.
在同一市场的CAP rate， 房租越高， 房价越高。
办公室的问题， 是因为现在大量的空置， 而不是房租的问题。
the only reason people think the interest rate has anything to do with market value is because they want to buy the property at a higher cap than the interest rate.
但是， 市场上， Class A/A-/B+ properties, always sell at lower CAP than the interest rate.
