I understand you are talking about subsitution, if Coke becomes too expansive I drink Pepsi lor. But shouldn't we be evaluating the effectiveness of CPI in measuring inflation and costs of living instead?
CPI basket consists of basic staple in our daily lives. We have very little alternative or none at all when it comes to housing, transport, sugar and flour. Wanton mee is not important lar.
When the CPI increases, I am very sure it will affact us in some ways.