AHH!! This is one of the question in the 03 HSC question. Its this: explain why the exchange rate can move in the opposite direction to the TWI. WHY??
Here's my answer (correct me!! please!): TWI is trade weighted, that is, the index varies according to the change in BOP over time. However the exchange rate is simply a bilateral measure (e.g. us to aud) of the rise/fall in purchasing power of AUD. So, while purchasing power increases, that is, an appreciation where import price falls, many may still wish to buy less imports.
Here's my answer (correct me!! please!): TWI is trade weighted, that is, the index varies according to the change in BOP over time. However the exchange rate is simply a bilateral measure (e.g. us to aud) of the rise/fall in purchasing power of AUD. So, while purchasing power increases, that is, an appreciation where import price falls, many may still wish to buy less imports.