What causes a shift in production possibility curve
A right shift in the production possibility curve may be caused by an improvement in technology.
For example: The economy might have installed a new machinery which might have increased the production capacity.
A left shift in the production possibility curve may be caused by a reduction in resources or inefficiency.
For example: Steel was being used to produce the product, but now the supply of steel in the economy has reduced which has caused a reduction in overall production.