With reference to the substitution effect, consider the following statements:

1. The substitution effect is the decrease in sales for a product that can be attributed to consumers switching to cheaper alternatives when its price rises.

2. When the price of a product or service increases but the buyer's income stays the same, the substitution effect generally kicks in.

3. A product may lose market share for many reasons, but the substitution effect is purely a reflection of frugality.

Which of the statements given above are correct?