With the big banks (JP Morgan, Morgan Stanley, Wells Fargo, etc) investing in tax lien certificates, rates that were in the low teens just 3-4 years ago are now bid down to 0-0.25% due to intense competition as your article states.

FORBES: Vulture Investing: What You Need To Know Before Bidding For Tax Liens

Existing lenders were in a power position, having to amend to approve the incremental debt used to fund the dividend, and second-lien investors in particular were concerned about the additional first-lien debt coming in ahead of them.

FORBES: Dividend finance rises on strong credit conditions

Of course, second-lien debt is a niche product for issuers that require higher leverage than is usually available in the first-lien market, but that in many cases are locked out of the regular-way high-yield bond market because of size, credit quality, or complexity.

FORBES: Connect