Which type of type of accounting change/error and if it will be accounted for prospectively or retrospectively

1. The company has never recorded an allowance for doubtful accounts. Historical averages suggest that 5% of customers never pay.

2. Production of one of the companys products has slowed down, resulting in the idling of a portion of the manufacturing facility in 2021. The company believes this represents a permanent asset impairment of its factory and equipment.

3. The companys actuaries will update the mortality tables used to calculate the PBO for the pension plan in 2021. This change will cause the PBO to increase.