The function downloads US stock-market data provided
by Robert Shiller which he used in his book
‘Irrational Exhuberance’. Since the data are
provided in Excel format, package readxl is
required.
The downloaded Excel gets a date prefix (today in
format YYYYMMDD
) and is stored in directory
dest.dir
. Before any download is attempted,
the function checks whether a file with today's
prefix exist in dest.dir
; if yes, the file is
used.