expenses of day to day life

It depends on economical up and down of a country.

The impact of a change in interest rates on bond prices is known as price effect.To make u clear the effect of change in the price of a particular commodity on the demand for that commodity is known as price effect.The price effect can further be seperated into substitution effect and the income effect.In substitution effect, demand changes because the good's price has changed relative to other goods whereas in income effect the demand changes because the change in price has affected the consumer's purchasing power.