We show how to measure the welfare effects arising from increased data availability. When lenders have more data on prospective borrower costs, they can charge prices that are more aligned with these costs. This increases total social welfare, and transfers surplus from borrowers to lenders. We show that the magnitudes of the welfare changes can be estimated using only quantity data and variation in prices. We apply the methodology on bankruptcy flag removals, and find that removing prior bankruptcy information increases the surplus of previously bankrupt consumers substantially, at the cost of decreasing total social welfare modestly, suggesting that flag removals have low efficiency costs for redistributing surplus to previously bankrupt borrowers.