True, but the figures can be misleading. The US economy is probably 4x the size it was in 1978, so without these productivity advances we'd need 4x as many book

True, but the figures can be misleading. The US economy is probably 4x the size it was in 1978, so without these productivity advances we'd need 4x as many book-keepers and accountants. Whether the economy could have grown to 4x the size without productivity advances like spreadsheets is a related question.