The economy is a complex system because market participants do not act independently but adjust their behavior to other agents and to the outcome which emerges from their joint actions (Arthur, 2014). Dependencies among participants can impede policy makers capabilities to influence or steer the course of the economy. Kambhu et al. (2007) argue that to influence developments in financial markets, for instance to prevent crises from spreading, there are only “coarse or indirect options” available for policy makers. Similar to crises which propagate through a complex system, interventions might result in unintended side effects which can also disseminate through the system. Thus, in a complex system, unintended consequences of policy efforts may well be the rule. Policy makers try to ward off or mitigate negative consequences for the economy and society during periods of crisis. For instance, during the Covid crisis large scale support programs for firms in Western economies were set up to avoid bankruptcies. Similarly, during the sovereign debt crisis in the Eurozone, the European Central Bank (ECB) set up large scale asset purchase programs as well as additionally longer-term refinancing operations (LTRO) which provided immediate support to financial market participants’ liquidity positions and thereby prevented a melt-down of the financial system. During these periods, immediate and abundant liquidity supply is of utmost importance. Meanwhile, crisis measures, due to their massive scale and non-specific target group, may entail unknown or unintended side effects for instance on competition among market participants, firms’ investment behavior, or changes in lending strategies and risk taking behavior of banks. Likewise, new regulatory frameworks such as the introduction of new markets can have consequences previously not thought of. For policy makers it is important to know direct effects of policy interventions but also to be aware of the possibility and impact of indirect or unexpected side effects in order to evaluate measures taken and to learn for future design of regulation or intervention.

Unconventional monetary policy measures like asset purchase programs aim to reduce certain securities' yield and alter financial institutions' investment behavior. These measures increase the institutions' market value of securities and add to their equity positions. We show that the extent of this recapitalization effect crucially depends on the securities' accounting and valuation methods, country-level regulation, and maturity structure. We argue that future research needs to consider these factors when quantifying banks' recapitalization effects and consequent changes in banks' lending decisions to the real sector.

Unconventional monetary policy measures like asset purchase programs aim to reduce certain securities' yield and alter financial institutions' investment behavior. These measures increase the institutions' market value of securities and add to their equity positions. We show that the extent of this recapitalization effect crucially depends on the securities' accounting and valuation methods, country-level regulation, and maturity structure. We argue that future research needs to consider these factors when quantifying banks' recapitalization effects and consequent changes in banks' lending decisions to the real sector.

We study the transmission channels from central banks’ quantitative easing programs via the banking sector when central banks start purchasing corporate bonds. We find evidence consistent with a “capital structure channel” of monetary policy. The announcement of central bank purchases reduces the bond yields of firms whose bonds are eligible for central bank purchases. These firms substitute bank term loans with bond debt, thereby relaxing banks’ lending constraints: banks with low tier-1 ratios and high nonperforming loans increase lending to private (and profitable) firms, which experience a growth in investment. The credit reallocation increases banks’ risk-taking in corporate credit.

Asset purchase programmes (APPs) may insulate banks from having to terminate relationships with unproductive customers. Using administrative plant and bank data, we test whether APPs impinge on industry dynamics in terms of plant entry and exit. Plants in Germany connected to banks with access to an APP are approximately 20% less likely to exit. In particular, unproductive plants connected to weak banks with APP access are less likely to close. Aggregate entry and exit rates in regional markets with high APP exposures are also lower. Thus, APPs seem to subdue Schumpeterian cleansing mechanisms, which may hamper factor reallocation and aggregate productivity growth.

• The world economy is booming. The global upswing is investment-driven, and since investment goods usually have a large import content, it is no surprise that world trade has been buoyant during winter. The very expansionary US fiscal policy (tax reform and lifting of spending caps) could give an additional shortterm stimulus for the world economy. • However, we forecast world trade to slow down during 2018. The US administration’s announcement of high tariffs on steel and aluminium comes close to triggering a spiral into a broader trade conflict. Moreover, the globalization of value chains has been slowing down since the financial crisis due to the industrial upgrading in China and in other emerging economies that has declined processing trade. In addition, some types of manufacturing jobs have returned to source countries (reshoring) in response to technology innovation and lower labour costs differentials. • The euro area is in the middle of a broad based cyclical upswing. Higher exports and improved expectations have induced firms to invest more into equipment, as capacity utilization has been above average for some time now and is still increasing, and financing costs are very low. However, recent soft indicators, but also industrial production have been surprisingly downbeat, and there was some turbulence in financial markets, which suggests some caution. • The ECB will probably stop its asset purchase program at the end of 2018, but only later in 2019 start raising interest rates. Fiscal policy in the euro area is slightly expansionary this year, and a notable fiscal stimulus in France and in Germany is to be expected for 2019. • Overall, we forecast euro area GDP to expand by 2.2% in 2018 and by 1.6% in 2019. Accelerating wage dynamics will, together with higher price setting powers of firms and the recent increase in oil prices, cause consumer price inflation rising to nearly to 2% in 2019. Uncertainty, is however substantial, as a slight slowdown cannot be ruled out, which would also impact inflation dynamics.

Die Europäische Zentralbank (EZB) hat mit dem Securities Markets Programme (SMP) im Mai 2010 ein Instrument unkonventioneller Geldpolitik eingeführt. Im Rahmen des SMP erwarb sie im Wert von 218 Mrd. Euro Staatsanleihen ausgewählter Länder, welche erhöhten Risikoaufschlägen am Kapitalmarkt ausgesetzt waren. Eine mögliche Nebenwirkung solcher Ankaufprogramme ist es, auch jene Banken zu stützen, die nicht zum direkten Adressatenkreis gehören, aber Anleihen betroffener Länder in ihren Portfolios hielten. Möglicherweise resultierende Refinanzierungs-, Ertrags-, und Liquiditätsvorteile für bevorteilte Banken könnten zu Wettbewerbsverzerrungen führen. Dieser Beitrag betrachtet deshalb die Wertpapierportfolios regionaler deutscher Banken, um den kausalen Effekt des SMP auf das Wettbewerbsverhalten zu identifizieren. Die empirischen Befunde belegen in der Tat eine statistisch nachweisbare Zunahme der lokalen Marktanteile jener regionalen Banken, welche Anleihen in ihren Portfolios hielten, die Teil des SMP waren. Während dieses Ergebnis somit einen Beleg für die Existenz unbeabsichtigter Nebenwirkungen unkonventioneller Geldpolitik darstellt, so ist auch festzuhalten dass diese Wettbewerbseffekte ausgesprochen klein sind. Somit ist zumindest für den regionalen Bankenmarkt in Deutschland keine nennenswerte Verwerfung aufgrund dieses Ankaufprogramms festzustellen.