Are junk bonds advisable to be inside a bond portfolio that has the objective of generating stable income for a retiree?
Junk Bonds (aka High Yield bonds) are typically those bonds from issues with credit ratings below BBB-. Not all such companies are big risks. They are just less financially sound than other, higher rated, companies. If you are not comfortable doing the analysis yourself, you should consider investing in a mutual fund, ETF, or unit trust that invests in high yield bonds. You get access to "better quality" issues because a huge amount of the debt markets goes to the institutional channels, not to the retail markets. High yield (junk) bonds can make up a part of your portfolio, and are a good source of regular income. As always, you should diversify and not have everything you own in one asset class. There are no real rules of thumb for asset allocation -- it all depends on your risk tolerance, goals, time horizon, and needs. If you don't trust yourself to make wise decisions, consult with a professional whom you trust.