1) If your property is not under rent control, you have the ability to raise rent to market prices with proper warning. In SF, I have to give tenants a one month warning for up to a 10% increase and a two month warning for up to 60%. Rent control limits to an inflation index, usually around 2% a year, which is why initial pricing and tenant turnover is important for better profitability.
If you watched the video, he goes into a discussion about shocks (about 8 minutes in) like bad investments but how they don't really matter as much if r (rate of return) is greater than g, the rate of economic growth. If r = 5% and g = 1%, then you can lose 80% (the difference) and still be ahead because the return on the remaining 20% has paced with economic growth.
These days, low-risk bond yields aren’t enough to meet most income needs. When investing in bonds, the income typically comes as coupon payments – contractually guaranteed interest payments at predictable intervals. There are many kinds of bond income available, so you must strike a balance between reaching for higher income (yield) and limiting risk.
My reasons for diversifying income are simple: I want to be able to quit my day job eventually. But your reasons may be different, maybe your job isn’t that secure or your co-workers are starting to feel the pressure. It really doesn’t matter why you diversify your sources of income, what matters is that you do it. Making money won’t happen overnight with second sources of income so if you wait until it’s too late you’ll be screwed.