Newspaper accounts about Switzerland showing social mobility (4-2-6)
I believe the answer is:
rags-to-riches
'social mobility' is the definition.
(I know that Rags to riches is a type of upward social mobility)
'newspaper accounts about switzerland' is the wordplay.
'newspaper' becomes 'rag' (informal term for a newspaper).
'accounts' becomes 'stories' (story is a kind of account).
'about' is an insertion indicator.
'switzerland' becomes 'ch' (short for Confoederatio Helvetica, its Latin name).
'stories' enclosing 'ch' is 'storiches'.
'rag'+'storiches'='RAGS-TO-RICHES'
'showing' is the link.
(Other definitions for rags-to-riches that I've seen before include "Description of story of worldly success" , "Describing a journey from poverty to wealth" , "Describing a person's progression from poverty to wealth" , "(Of a story) describing progression from poverty to wealth" , "'From poverty to extreme wealth'" .)