It was greed
The 'it was greed' spin on scheme collapse, is a popular one, since it is actually true. Blaming an economic collapse on greed seems as pointless as blaming the crash of an aircraft on gravity, but it is not as stupid as it seems. The greed that caused economic collapse, was your greed, which taxed their life away and grew the coercive part of society around the voluntary part until the coercive part collapsed in on the voluntary part. You are of course not actually going to say that.
It is important that during all schemes you make the slaves apparent accomplices in your scheme. This way their protests are postponed. Most schemes advise you to get the tax slaves to put their signature of agreement under your license to kill, because you tell them you are coercing their neighbors for their benefit. After doing so you of course go to their neighbors and repeat the procedure. This approval is not required to get moral justification for extortion, since nothing can, but it is required to prevent the tax slave from protesting on principle. He already compromised his principles on signing and is less likely to object to his own coercion after agreeing to his neighbors coercion, certainly if you implied that his signature was pivotal.
The tax slave his own greed then is a cause of the economic collapse and since he unconsciously knows he betrayed principles for short term greed, 'greed was the cause spin' will make him self attack over his own losses in the economic crash.
Remember: keep them focused on the perceived evils of those they are not coerced by