This paper investigates the impact of the ECB/Eurosystem's Public Sector Purchase Program (PSPP) on prices and liquidity of German Treasury securities, in short Bunds. Our focus is on the scarcity effects of the asset purchases and possible market distortions.
ContributionThis is the first study that matches high-frequency data on official-sector asset purchases with high-frequency inter-dealer sovereign bond data. This enables a precise identification of the intra-day impact of bond purchases via scarcity effects. Due to the presence of a large unidirectional buyer, potential demand-supply imbalances may arise. The impact of such imbalances on the market functioning, especially liquidity provision, are studied in detail.
ResultsThe results of this study show significant and positive price impacts of PSPP purchases on Bunds, both at the minute and daily frequencies. This highlights the importance of scarcity in bond markets. These intended price effects are not without side effects. We find that large-scale asset purchases affect liquidity conditions in the Bund market. Standard liquidity measures such as bid-ask spreads and order book depth suggest a decline in market quality. We further show that price impacts depend on market conditions. They are substantially higher in times of market stress and during episodes of high yields, when the demand for government bonds is suppressed. This paper investigates the scarcity effects of quantitative easing (QE) policies, drawing on intra-day transaction-level data for German government bonds, purchased under the Public Sector Purchase Program (PSPP) of the ECB/Eurosystem. This paper is the first to match high-frequency QE purchase data with high-frequency inter-dealer data. We find economically significant price impacts at high (minuteby-minute) and low (daily) frequencies, highlighting the relevance of scarcity effects in bond markets. Asset purchase policies are not without side effects, though, as the induced scarcity has an adverse impact on liquidity conditions as measured by bid-ask spreads and inter-dealer order book depth. We further show that the price impact varies greatly with market conditions: it is considerably higher during episodes of illiquidity and when yields are higher.