They don't even need this software, they just need their mortgages underwritten by the same small handful of banks. The banks aren't willing to put the write d

They don't even need this software, they just need their mortgages underwritten by the same small handful of banks. The banks aren't willing to put the write downs on their balance sheets. They can lose money for years due to vacancy but those losses only matter when everyone realizes the rating on that bundle of mortgages isn't AAA. Lowering the rent would force them to reprice the asset right now.