Nested Models and Model Uncertainty
Alexander Kriwoluzky, Christian A. Stoltenberg
Scandinavian Journal of Economics,
No. 2,
2016
Abstract
Uncertainty about the appropriate choice among nested models is a concern for optimal policy when policy prescriptions from those models differ. The standard procedure is to specify a prior over the parameter space, ignoring the special status of submodels (e.g., those resulting from zero restrictions). Following Sims (2008, Journal of Economic Dynamics and Control 32, 2460–2475), we treat nested submodels as probability models, and we formalize a procedure that ensures that submodels are not discarded too easily and do matter for optimal policy. For the United States, we find that optimal policy based on our procedure leads to substantial welfare gains compared to the standard procedure.
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Does the Technological Content of Government Demand Matter for Private R&D? Evidence from US States
Viktor Slavtchev, Simon Wiederhold
American Economic Journal: Macroeconomics,
No. 2,
2016
Abstract
Governments purchase everything from airplanes to zucchini. This paper investigates the role of the technological content of government procurement in innovation. In a theoretical model, we first show that a shift in the composition of public purchases toward high-tech products translates into higher economy-wide returns to innovation, leading to an increase in the aggregate level of private R&D. Using unique data on federal procurement in US states and performing panel fixed-effects estimations, we find support for the model's prediction of a positive R&D effect of the technological content of government procurement. Instrumental-variable estimations suggest a causal interpretation of our findings.
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The Diablo 3 Economy: An Agent Based Approach
Makram El-Shagi, Gregor von Schweinitz
Computational Economics,
No. 2,
2016
Abstract
Designers of MMOs such as Diablo 3 face economic problems much like policy makers in the real world, e.g. inflation and distributional issues. Solving economic problems through regular updates (patches) became as important to those games as traditional gameplay issues. In this paper we provide an agent framework inspired by the economic features of Diablo 3 and analyze the effect of monetary policy in the game. Our model reproduces a number of features known from the Diablo 3 economy such as a heterogeneous price development, driven almost exclusively by goods of high quality, a highly unequal wealth distribution and strongly decreasing economic mobility. The basic framework presented in this paper is meant as a stepping stone to further research, where our evidence is used to deepen our understanding of the real-world counterparts of such problems. The advantage of our model is that it combines simplicity that is inherent to model economies with a similarly simple observable counterpart (namely the game environment where real agents interact). By matching the dynamics of the game economy we can thus easily verify that our behavioral assumptions are good approximations to reality.
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Exit Expectations and Debt Crises in Currency Unions
Alexander Kriwoluzky, G. J. Müller, M. Wolf
IWH Discussion Papers,
No. 18,
2015
Abstract
Membership in a currency union is not irreversible. Exit expectations may emerge during sovereign debt crises, because exit allows countries to reduce their liabilities through a currency redenomination. As market participants anticipate this possibility, sovereign debt crises intensify. We establish this formally within a small open economy model of changing policy regimes. The model permits explosive dynamics of debt and sovereign yields inside currency unions and allows us to distinguish between exit expectations and those of an outright default. By estimating the model on Greek data, we quantify the contribution of exit expectations to the crisis dynamics during 2009 to 2012.
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Global Food Prices and Business Cycle Dynamics in an Emerging Market Economy
Oliver Holtemöller, Sushanta Mallick
Abstract
This paper investigates a perception in the political debates as to what extent poor countries are affected by price movements in the global commodity markets. To test this perception, we use the case of India to establish in a standard SVAR model that global food prices influence aggregate prices and food prices in India. To further analyze these empirical results, we specify a small open economy New-Keynesian model including oil and food prices and estimate it using observed data over the period from 1996Q2 to 2013Q2 by applying Bayesian estimation techniques. The results suggest that big part of the variation in inflation in India is due to cost-push shocks and, mainly during the years 2008 and 2010, also to global food price shocks, after having controlled for exogenous rainfall shocks. We conclude that the inflationary supply shocks (cost-push, oil price, domestic food price and global food price shocks) are important contributors to inflation in India. Since the monetary authority responds to these supply shocks with a higher interest rate which tends to slow growth, this raises concerns about how such output losses can be prevented by reducing exposure to commodity price shocks and thereby achieve higher growth.
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The Schumpeterian Growth Paradigm
Philippe Aghion, Ufuk Akcigit, Peter Howitt
Annual Review of Economics,
2015
Abstract
In this review, we argue that the Schumpeterian growth paradigm, which models growth as resulting from innovations involving creative destruction, sheds light on several aspects of the growth process that cannot be properly addressed by alternative theories. We focus on three important aspects for which Schumpeterian growth theory delivers predictions that distinguish it from other growth models, namely, (a) the role of competition and market structure, (b) firm dynamics, and (c) the relationship between growth and development.
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A Weighty Issue Revisited: The Dynamic Effect of Body Weight on Earnings and Satisfaction in Germany
Frieder Kropfhäußer, Marco Sunder
Applied Economics,
No. 41,
2015
Abstract
We estimate the relationship between changes in the body mass index (bmi) and wages or satisfaction, respectively, in a panel of German employees. In contrast to previous findings, our dynamic models indicate an inverse u-shaped association between bmi and wages. As the implied maximum occurs in the ‘overweight’ category, the positive trend in weight may not yet constitute a major limitation to productivity. Further investigation points out a stronger association among young workers and workers with jobs that are less protected. Work satisfaction of young workers is associated with bmi beyond the effect of earnings.
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The Joint Dynamics of Sovereign Ratings and Government Bond Yields
Makram El-Shagi, Gregor von Schweinitz
Abstract
In the present paper, we build a bivariate semiparametric dynamic panel model to repro-duce the joint dynamics of sovereign ratings and government bond yields. While the individual equations resemble Pesaran-type cointegration models, we allow for different long-run relationships in both equations, nonlinearities in the level effect of ratings, and asymmetric effects in changes of ratings and yields. We find that the interest rate equation and the rating equation imply significantly different long-run relationships. While the high persistence in both interest rates and ratings might lead to the misconception that they follow a unit root process, the joint analysis reveals that they converge slowly to a joint equilibrium. While this indicates that there is no vicious cycle driving countries into default, the persistence of ratings is high enough that a rating shock can have substantial costs. Generally, the interest rate adjusts rather quickly to the risk premium that is in line with the rating. For most ratings, this risk premium is only marginal. However, it becomes substantial when ratings are downgraded to highly speculative (a rating of B) or lower. Rating shocks that drive the rating below this threshold can increase the interest rate sharply, and for a long time. Yet, simulation studies based on our estimations show that it is highly improbable that rating agencies can be made responsible for the most dramatic spikes in interest rates.
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Is There Monopsonistic Discrimination against Immigrants?
Boris Hirsch, Elke J. Jahn
ILR Review,
No. 3,
2015
Abstract
The authors investigate immigrants’ and natives’ labor supply to the firm within an estimation approach based on a dynamic monopsony framework. Applying duration models that account for unobserved worker heterogeneity to a large administrative employer–employee data set for Germany, they find that immigrants supply labor less elastically to firms than do natives. Under monopsonistic wage setting, the estimated elasticity differential predicts a 7.7 log points wage penalty for immigrants thereby accounting for the entire unexplained native–immigrant wage differential of 5.8 to 8.2 log points. When further distinguishing immigrant groups differing in their time spent in the German labor market, their immigration cohort, and their age at entry, the authors find that the observed unexplained wage differential is larger for those groups that show a larger elasticity differential relative to natives. These findings not only suggest that search frictions are a likely cause of employers’ more pronounced monopsony power over their immigrant workers but also imply that employers profit from discriminating against immigrants.
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