What effect does lowering the estimate for doubtful accounts have on the income statement and balance sheet?

Lowering your provision i.e. Reversing some of your previous Doubtful Debt estimate, will Increase your Income for the period CR Doubtful Debt reclaim (Or something like that), and it will reduce your CR Provision

Before
Debtor 100
Provision Doubt Debt (40)
Accum Profit (60)

After
Debtor 100
Provision Doubt Debt (20)
Income (20)
Accum Profit (60)