I assume that it means they’re spending rather than saving that discretionary income, and don’t have a buffer available of more than a single pay period (usuall

I assume that it means they’re spending rather than saving that discretionary income, and don’t have a buffer available of more than a single pay period (usually 2 weeks). That money may also be committed to long-term contracts with service providers and not readily available for redirection. It’s sometimes a reflection of financial priorities rather than raw income.