We assess the yield impact of asset purchases within the European Central Bank׳s (ECB) Securities Markets Programme (SMP) in five euro area sovereign bond markets from 2010–11. In addition to large announcement effects, we find an impact of approximately −3 basis points at the five-year maturity for purchases of 1/1000 of the outstanding debt. Bond yield volatility and tail risk are lower on intervention days for most SMP countries. A dynamic specification points to both transitory and long-run effects. Purchases improved liquidity conditions and reduced default-risk premia, while the signaling of future low interest rates did not play a role.

We propose an observation-driven dynamic factor model for mixed-measurement and mixed-frequency panel data. Time series observations may come from a range of families of distributions, be observed at different frequencies, have missing observations, and exhibit common dynamics and cross-sectional dependence due to shared dynamic latent factors. A feature of our model is that the likelihood function is known in closed form. This enables parameter estimation using standard maximum likelihood methods. We adopt the new framework for signal extraction and forecasting of macro, credit, and loss given default risk conditions for U.S. Moody's-rated firms from January 1982 to March 2010.