Among the many mechanisms available to a human cell is the ability to compensate for a defective gene.  If a gene becomes mutated so that it no longer functions correctly, other proteins (genes are the blueprints for proteins), in some instance, can pick up the functional slack for the damaged gene.  While this is not always the case and I know of no case where another protein can completely replace the damage gene, it does happen more often than one would think.  The replacement, though, is always less efficient than the original.  And in a great deal of circumstances a mutated gene becomes a death sentence.  More than half of all cancers have a mutated gene called p53 and if you have a mutated p53 you will almost certainly develop cancer.

All economies are composed of two things… supply and demand.  There are people who demand things, smartphones, computers, cars, porn etcetera.  People who supply things, HTC, Dell, Ford, Vivid.  An economy is very much like a eukaryotic cell.  It is very complex, there are overlapping pathways, there are built in redundancies (there are many companies offering smartphones with many of the same features) and the loss of any single entity does not automatically doom the system to failure.  Like everything else, there are exceptions.  Some genes, if lost, will result in catastrophe for the cell (and in some instances the body as a whole).  While de Gaulle’s quip about cemeteries and indispensable people is certainly correct as regards people, it does not apply to proteins or economies.  The consumer is two-thirds of the U.S. economy and without those consumers there is no U.S. economy.  A fact we are all now very much aware.  So what does an economy due when the indispensable one keels over dead?  You look for some economic plasticity.  Just as another gene can sometimes “fill-in” for a damaged gene, the Federal government sometimes has to fill-in for the damaged consumer.  Is it optimal?  No of course not.  In the cell, the substitute gene usually can only keep the cell going long enough so that it can be destroyed in an orderly fashion thereby preventing damage to neighboring cells (a process called apoptosis).  Similarly, the Federal government cannot keep the U.S. economy going indefinitely, but it can keep it going long enough for consumers (and by extension businesses) to regain their footing and start moving forward again.

John Maynard Keynes (1883–1946)

Cell (~3 billion years ago[for prokaryote]-present)