Information Feedback in Temporal Networks as a Predictor of Market Crashes
Stjepan Begušić, Zvonko Kostanjčar, Dejan Kovač, Boris Podobnik, H. Eugene Stanley
Complexity,
September
2018
Abstract
In complex systems, statistical dependencies between individual components are often considered one of the key mechanisms which drive the system dynamics observed on a macroscopic level. In this paper, we study cross-sectional time-lagged dependencies in financial markets, quantified by nonparametric measures from information theory, and estimate directed temporal dependency networks in financial markets. We examine the emergence of strongly connected feedback components in the estimated networks, and hypothesize that the existence of information feedback in financial networks induces strong spatiotemporal spillover effects and thus indicates systemic risk. We obtain empirical results by applying our methodology on stock market and real estate data, and demonstrate that the estimated networks exhibit strongly connected components around periods of high volatility in the markets. To further study this phenomenon, we construct a systemic risk indicator based on the proposed approach, and show that it can be used to predict future market distress. Results from both the stock market and real estate data suggest that our approach can be useful in obtaining early-warning signals for crashes in financial markets.
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On DSGE Models
Lawrence J. Christiano, Martin S. Eichenbaum, Mathias Trabandt
Journal of Economic Perspectives,
No. 3,
2018
Abstract
The outcome of any important macroeconomic policy change is the net effect of forces operating on different parts of the economy. A central challenge facing policymakers is how to assess the relative strength of those forces. Economists have a range of tools that can be used to make such assessments. Dynamic stochastic general equilibrium (DSGE) models are the leading tool for making such assessments in an open and transparent manner. We review the state of mainstream DSGE models before the financial crisis and the Great Recession. We then describe how DSGE models are estimated and evaluated. We address the question of why DSGE modelers—like most other economists and policymakers—failed to predict the financial crisis and the Great Recession, and how DSGE modelers responded to the financial crisis and its aftermath. We discuss how current DSGE models are actually used by policymakers. We then provide a brief response to some criticisms of DSGE models, with special emphasis on criticism by Joseph Stiglitz, and offer some concluding remarks.
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19.04.2018 • 7/2018
Joint Economic Forecast Spring 2018: Germany’s Economic Experts Raise Forecast Slightly
Berlin, 19 April – Germany’s leading economic experts raised their forecasts for 2018 and 2019 slightly in their Spring Joint Economic Forecast released on Thursday in Berlin. They now expect economic growth of 2.2 percent for this year and 2.0 percent for 2019, versus 2.0 percent and 1.8 percent respectively in their autumn forecast. “The German economy is still booming, but the air is getting thinner as unused capacities are shrinking“, notes Timo Wollmershaeuser, ifo Head of Economic Forecasting. Commenting on the new German government’s economic policy, he adds: “It is precisely when the government’s coffers are full that fiscal policy should reflect the implications of its actions for overall economic stability and the sustainability of public finances. The extension of statutory pension benefits outlined in the coalition agreement runs counter to the idea of sustainability.”
Oliver Holtemöller
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The Effects of Fiscal Policy in an Estimated DSGE Model – The Case of the German Stimulus Packages During the Great Recession
Andrej Drygalla, Oliver Holtemöller, Konstantin Kiesel
Abstract
In this paper, we analyse the effects of the stimulus packages adopted by the German government during the Great Recession. We employ a standard medium-scale dynamic stochastic general equilibrium (DSGE) model extended by non-optimising households and a detailed fiscal sector. In particular, the dynamics of spending and revenue variables are modeled as feedback rules with respect to the cyclical component of output. Based on the estimated rules, fiscal shocks are identified. According to the results, fiscal policy, in particular public consumption, investment, transfers and changes in labour tax rates including social security contributions prevented a sharper and prolonged decline of German output at the beginning of the Great Recession, suggesting a timely response of fiscal policy. The overall effects, however, are small when compared to other domestic and international shocks that contributed to the economic downturn. Our overall findings are not sensitive to the allowance of fiscal foresight.
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Progressive Tax-like Effects of Inflation: Fact or Myth? The U.S. Post-war Experience
Matthias Wieschemeyer, Bernd Süssmuth
IWH Discussion Papers,
No. 33,
2017
Abstract
Inflation and earnings growth can push some tax payers into higher brackets in the absence of inflation-indexed schedules. Moreover, inflation may affect the composition of individuals’ income sources. As a result, depending on the relative tax burden of labour and capital, inflation may decrease or increase the difference between before-tax and after-tax income. However, whether some and if so which percentiles of the income distribution net benefit from inflation via taxation is a widely unexplored question. We make use of a novel dataset on U.S. pre-tax and post-tax income distribution series provided by Pike ty et al. (2018) for the years 1962 to 2014 to answer this question. To this end, we estimate local projections to quantify dynamic effects. We find that inflation shocks increase progressivity of taxation not only contemporaneously but also with some repercussion of several years after the shock. While particularly the bottom two quintiles gain in share, it is not the top but the fourth quintile that lastingly loses.
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14.12.2017 • 39/2017
Cyclical upswing in Germany and in the world
At the turn of the year, the cyclical upswing in Germany continues. Gross domestic product is expected to increase by 2.2% in 2017, and because this year has seen significantly fewer working days than before, the rate of change amounts, adjusted for calendar effects, to even 2.5%. “The upswing is broad-based”, says Oliver Holtemöller, head of the Department Macroeconomics and IWH vice president. “For quite a long time now, significant increases in employment have been driving private incomes, consumption and housing construction. The latter was, in addition, stimulated by low interest rates.” Currently, German exports are benefiting from the vivid international economy. Not least since monetary policy in the euro area remains expansionary for the time being, we expect the upturn to continue in 2018 and production to increase again by 2.2%. Consumer price inflation is, with 1.7%, still moderate in both 2017 and 2018. Although domestic price pressures are on the rise, the effects of the energy price increase in 2017 expire in 2018, and the appreciation of the euro in the summer of 2017 will dampen price dynamics.
Oliver Holtemöller
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Macroprudential Policy and Intra-group Dynamics: The Effects of Reserve Requirements in Brazil
Chris Becker, Matias Ossandon Busch, Lena Tonzer
Abstract
This paper examines whether intra-group dynamics matter for the transmission of macroprudential policy. Using novel bank-level data on the Brazilian banking system, we investigate the effect of reserve requirements targeting headquarter banks’ deposit share on credit supply by their municipal bank branches. For identification purposes, we exploit that reserve requirements are adjusted following global economic cycles. Our results reveal a lending channel of reserve requirements for branches whose parent banks are more exposed to targeted deposits. Branch ownership and exposure to internal liquidity are central in explaining the results. Our findings reveal limitations in current macroprudential policy frameworks.
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28.09.2017 • 35/2017
Joint Economic Forecast—Autumn 2017: Upturn Remains Robust—Amid Mounting Tensions
The German economic upturn has gained both in terms of strength and breadth. In addition to consumer spending, external trade and investments are now also contributing to economic expansion. These are the conclusions drawn by the economic research institutes in their autumn report for the German federal government. Whereas the very high economic momentum in the first half of the current year will slow slightly, expansion of economic output this year and next will exceed production capacity growth. As a result, overall capacity utilization will increase, with economic output exceeding potential output. Gross Domestic Product is likely to grow by 1.9 percent this year and by 2 percent in 2018 (calendar-adjusted: 2.2 and 2.1 percent, respectively).
Oliver Holtemöller
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The Dynamic Effects of Works Councils on Plant Productivity: First Evidence from Panel Data
Steffen Müller, Jens Stegmaier
British Journal of Industrial Relations,
No. 2,
2017
Abstract
We estimate dynamic effects of works councils on labour productivity using newly available information from West German establishment panel data. Conditioning on plant fixed effects and control variables, we find negative productivity effects during the first five years after council introduction but a steady and substantial increase in the councils’ productivity effect thereafter. Our findings support a causal interpretation for the positive correlation between council existence and plant productivity that has been frequently reported in previous studies.
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Tail-risk Protection Trading Strategies
Natalie Packham, Jochen Papenbrock, Peter Schwendner, Fabian Wöbbeking
Quantitative Finance,
No. 5,
2017
Abstract
Starting from well-known empirical stylized facts of financial time series, we develop dynamic portfolio protection trading strategies based on econometric methods. As a criterion for riskiness, we consider the evolution of the value-at-risk spread from a GARCH model with normal innovations relative to a GARCH model with generalized innovations. These generalized innovations may for example follow a Student t, a generalized hyperbolic, an alpha-stable or a Generalized Pareto distribution (GPD). Our results indicate that the GPD distribution provides the strongest signals for avoiding tail risks. This is not surprising as the GPD distribution arises as a limit of tail behaviour in extreme value theory and therefore is especially suited to deal with tail risks. Out-of-sample backtests on 11 years of DAX futures data, indicate that the dynamic tail-risk protection strategy effectively reduces the tail risk while outperforming traditional portfolio protection strategies. The results are further validated by calculating the statistical significance of the results obtained using bootstrap methods. A number of robustness tests including application to other assets further underline the effectiveness of the strategy. Finally, by empirically testing for second-order stochastic dominance, we find that risk averse investors would be willing to pay a positive premium to move from a static buy-and-hold investment in the DAX future to the tail-risk protection strategy.
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