Risk transfer with CDOs

Modern bank management comprises both classical lending business and transfer of asset risk to capital markets through securitization. Sound knowledge of the risks involved in securitization transactions is a prerequisite for solid risk management. This paper aims to resolve a part of the opaqueness surrounding credit-risk allocation to tranches that represent claims of different seniority on a reference portfolio. In particular, this paper analyzes the allocation of credit risk to different tranches of a CDO transaction when the underlying asset returns are driven by a common macro factor and an idiosyncratic component. Junior and senior tranches are found to be nearly orthogonal, motivating a search for the whereabout of systematic risk in CDO transactions. We propose a metric for capturing the allocation of systematic risk to tranches. First, in contrast to a widely-held claim, we show that (extreme) tail risk in standard CDO transactions is held by all tranches. While junior tranches take on all types of systematic risk, senior tranches take on almost no non-tail risk. This is in stark contrast to an untranched bond portfolio of the same rating quality, which on average suffers substantial losses for all realizations of the macro factor. Second, given tranching, a shock to the risk of the underlying asset portfolio (e.g. a rise in asset correlation or in mean portfolio loss) has the strongest impact, in relative terms, on the exposure of senior tranche CDO-investors. Our findings can be used to explain major stylized facts observed in credit markets

CDOs and systematic risk : why bond ratings are inadequate

This paper analyzes the risk properties of typical asset-backed securities (ABS), like CDOs or MBS, relying on a model with both macroeconomic and idiosyncratic components. The examined properties include expected loss, loss given default, and macro factor dependencies. Using a two-dimensional loss decomposition as a new metric, the risk properties of individual ABS tranches can directly be compared to those of corporate bonds, within and across rating classes. By applying Monte Carlo Simulation, we find that the risk properties of ABS differ significantly and systematically from those of straight bonds with the same rating. In particular, loss given default, the sensitivities to macroeconomic risk, and model risk differ greatly between instruments. Our findings have implications for understanding the credit crisis and for policy making. On an economic level, our analysis suggests a new explanation for the observed rating inflation in structured finance markets during the pre-crisis period 2004-2007. On a policy level, our findings call for a termination of the 'one-size-fits-all' approach to the rating methodology for fixed income instruments, requiring an own rating methodology for structured finance instruments. JEL Classification: G21, G2

Risk transfer with CDOs and systemic risk in banking

Large banks often sell part of their loan portfolio in the form of collateralized debt obligations (CDO) to investors. In this paper we raise the question whether credit asset securitization affects the cyclicality (or commonality) of bank equity values. The commonality of bank equity values reflects a major component of systemic risks in the banking market, caused by correlated defaults of loans in the banks' loan books. Our simulations take into account the major stylized fact of CDO transactions, the non-proportional nature of risk sharing that goes along with tranching. We provide a theoretical framework for the risk transfer through securitization that builds on a macro risk factor and an idiosyncratic risk factor, allowing an identification of the types of risk that the individual tranche holders bear. This allows conclusions about the risk positions of issuing banks after risk transfer. Building on the strict subordination of tranches, we first evaluate the correlation properties both within and across risk classes. We then determine the effect of securitization on the systematic risk of all tranches, and derive its effect on the issuing bank's equity beta. The simulation results show that under plausible assumptions concerning bank reinvestment behaviour and capital structure choice, the issuing intermediary's systematic risk tends to rise. We discuss the implications of our findings for financial stability supervision. Klassifikation: G2

Risk Transfer with CDOs and Systemic Risk in Banking

Large banks often sell part of their loan portfolio in the form of collateralized debt obligations (CDO) to investors. In this paper we raise the question whether credit asset securitization affects the cyclicality (or commonality) of bank equity values. The commonality of bank equity values reflects a major component of systemic risks in the banking market, caused by correlated defaults of loans in the banks’ loan books. Our simulations take into account the major stylized fact of CDO transactions, the nonproportional nature of risk sharing that goes along with tranching. We provide a theoretical framework for the risk transfer through securitization that builds on a macro risk factor and an idiosyncratic risk factor, allowing an identification of the types of risk that the individual tranche holders bear. This allows conclusions about the risk positions of issuing banks after risk transfer. Building on the strict subordination of tranches, we first evaluate the correlation properties both within and across risk classes. We then determine the effect of securitization on the systematic risk of all tranches, and derive its effect on the issuing bank’s equity beta. The simulation results show that under plausible assumptions concerning bank reinvestment behaviour and capital structure choice, the issuing intermediary’s systematic risk tends to rise. We discuss the implications of our findings for financial stability supervision.

CDOs and Systematic Risk: Why bond ratings are inadequate

This paper analyzes the risk properties of typical asset-backed securities (ABS), like CDOs or MBS, relying on a model with both macroeconomic and idiosyncratic components. The examined properties include expected loss, loss given default, and macro factor dependencies. Using a two-dimensional loss decomposition as a new metric, the risk properties of individual ABS tranches can directly be compared to those of corporate bonds, within and across rating classes. By applying Monte Carlo Simulation, we find that the risk properties of ABS differ significantly and systematically from those of straight bonds with the same rating. In particular, loss given default, the sensitivities to macroeconomic risk, and model risk differ greatly between instruments. Our findings have implications for understanding the credit crisis and for policy making. On an economic level, our analysis suggests a new explanation for the observed rating inflation in structured finance markets during the pre-crisis period 2004-2007. On a policy level, our findings call for a termination of the 'one-size-fits-all' approach to the rating methodology for fixed income instruments, requiring an own rating methodology for structured finance instruments.Credit Risk, Risk Transfer, Systematic Risk

Simulation-Based Pricing of Convertible Bonds

We propose and empirically study a pricing model for convertible bonds based on Monte Carlo simulation. The method uses parametric representations of the early exercise decisions and consists of two stages. Pricing convertible bonds with the proposed Monte Carlo approach allows us to better capture both the dynamics of the underlying state variables and the rich set of real-world convertible bond specifications. Furthermore, using the simulation model proposed, we present an empirical pricing study of the US market, using 32 convertible bonds and 69 months of daily market prices. Our results do not confirm the evidence of previous studies that market prices of convertible bonds are on average lower than prices generated by a theoretical model. Similarly, our study is not supportive of a strong positive relationship between moneyness and mean pricing error, as argued in the literature.Convertible bonds, Pricing, American Options, Monte Carlo simulation

Ausmaß und Ursachen von Niedriglöhnen im ostdeutschen Dienstleistungsgewerbe

In recent years, employment has grown noticeably in Germany. Although this is good news, some people criticize that many jobs are low-paid, i.e. the wage is less than two thirds of the medium wage. An eye-catching example is the service sector in Eastern Germany. However, a systematic analysis of this sector in Eastern Germany is missing until now. The article closes this gap in the literature. Concerning the whole service sector in Eastern Germany, about 25 percent of the employees get a low (gross) wage. This is not much more than the average of all sectors. However, in some branches of the service sector, much more employees get low wages. More than 40% of the employees of retail trade, restaurant business and services near to companies (“unternehmensnahe Dienstleistungen”) are paid low. The probability to get a low wage is significantly higher for women and the so-called minijobbers. Since the tax system adjusts differences, all calculations were also done for net wages. On the one hand, the part of low-paid workers decreases for all branches and all subpopulations. On the other hand, the probability to get a low wage does not differ anymore between minijobbers and full-time employees. Thus, the tax system does not only reduce low-paid employment, it also changes its structure.

Going full circle: the need for procedural perspectives on EU responsiveness

Research on policy responsiveness of the European Union has adopted the systemic model from national contexts. This focusses on the static congruence or the dynamic adaptation of aggregated policy output and similarly aggregated public opinion. Approaches in this vein provide relevant insights and uncover a surprising degree of EU responsiveness. Yet, this debate contribution argues that they only insufficiently capture indirect accountability chains and the emerging challenges of public EU politicization and mediatization. We establish the need for procedural perspectives that addresses how the different EU institutions perceive and digest public opinion and subsequently influence it through communication. To further this research agenda, we sketch the contours of a procedural model by highlighting possible variation at the input, throughput and output stages. Going full circle, we suggest, allows us to better understand the responses to public opinion and their wider implications for the societal acceptance of the unfinished supranational polity

A comparison of in- and ex-situ shear bands in metallic glass by transmission electron microsopy

Plastic deformation of metallic glasses performed at temperatures well below the glass transition proceeds via the formation of shear bands. In this contribution shear bands originating from in situ tensile tests of Al$_{88}$Y$_{7}$Fe$_{5}$ melt-spun ribbons conducted in a transmission electron microscope are compared with ones which had formed ex situ during cold rolling. The observed contrasts for shear bands generated in situ at the edges of thin electron-transparent foils are shown to be related to a meniscus-like foil thickness reduction. In comparison with ex situ samples, alternating contrast changes due to volume changes are missing and the shear band width is a factor of 15 larger. The meniscus-like shear band profile is accounted for by the thin foil allowing volume increase due to shear deformation to annihilate via the free surfaces of the thin foil and the sheared zones to widen.Comment: submitted to Scripta Materiali