international working group on price indices fourth meeting washington 22 24 april 1998 rósmundur gudnason statistics iceland comparison of different sources for weights selected groups in the icelandic cpi consumers bar code cash receipts vs scanner data from supermarkets 1 hbs are many cases main source new when revisions made use collected 1995 offer possibilities this respect one way to check information is compare results with based that was year about same expenditures 1997 also gathered aggregated covering 400 and items each involved food beverages some other altogether accounting 19 total weight these were classified according coicop classification 2 then compared available supermarket chain found table