You are correct. It doesn't look like treasury bond issuance increased as a result of the Fed bond buying, so the increased US debt levels since QE began are primarily a function of reduced tax income as a result of the economic downturn and spending imbalances. However, I believe QE still pulls investment forward in time by maintaining interest rates artificially low. It also encourages misallocation of resources. If it was the answer to all ill's why stop? The past history of money printing has not been good.