Forecasting Economic Activity Using a Neural Network in Uncertain Times: Monte Carlo Evidence and Application to the
German GDP
Oliver Holtemöller, Boris Kozyrev
IWH Discussion Papers,
No. 6,
2024
Abstract
In this study, we analyzed the forecasting and nowcasting performance of a generalized regression neural network (GRNN). We provide evidence from Monte Carlo simulations for the relative forecast performance of GRNN depending on the data-generating process. We show that GRNN outperforms an autoregressive benchmark model in many practically relevant cases. Then, we applied GRNN to forecast quarterly German GDP growth by extending univariate GRNN to multivariate and mixed-frequency settings. We could distinguish between “normal” times and situations where the time-series behavior is very different from “normal” times such as during the COVID-19 recession and recovery. GRNN was superior in terms of root mean forecast errors compared to an autoregressive model and to more sophisticated approaches such as dynamic factor models if applied appropriately.
Read article
Homepage
German economy in transition ‒ weak momentum, low potential growth The Joint Economic Forecast Project Group forecasts a 0.1% decline in Germany's gross domestic product in 2024.…
See page
Charts
Info Graphs Sometimes pictures say more than a thousand words. Therefore, we selected a few graphs to present our main topics visually. If you should have any questions or would…
See page
Stock of fixed assets
Stock of fixed assets Gross fixed capital formation Gross fixed capital formation includes the purchase of permanent and reproducible fixed assets as well as created fixed assets…
See page
Exchange Rate Regime, Real Misalignment and Currency Crises
Oliver Holtemöller, Sushanta Mallick
Economic Modelling,
No. 34,
2013
Abstract
Based on 69 sample countries, this paper examines the effect of macroeconomic fundamentals on real effective exchange rates (REER) in these sample countries. Using the misalignment of actual REER from its equilibrium level, we have estimated the factors explaining the extent of currency over- or under-valuation. Overall, we find that the higher the flexibility of the currency regime, the lower is the misalignment. The estimates are robust to different sub-samples of countries. We then explore the impact of such misalignment on the probability of a currency crisis in the next period, indicating the extent to which misalignment could be used as a leading indicator of a potential crisis. This paper thus makes a new contribution to the debate on the choice of exchange rate regime by bringing together real exchange rate misalignment and currency crisis literature.
Read article
The Transition to Post-industrial BMI Values among US Children
Marco Sunder, Ariane Breitfelder, John Komlos
American Journal of Human Biology,
2009
Abstract
The trend in the BMI values of US children has not been estimated very convincingly because of the absence of longitudinal data. Our objective is to estimate time series of BMI values by birth cohorts instead of measurement years. We use five regression models to estimate the BMI trends of non-Hispanic US-born black and white children and adolescents ages 2-19 between 1941 and 2004. The increase in BMIZ values during the period considered was 1.3 (95% CI: 1.16; 1.44) among black girls, 0.8 for black boys, 0.7 for white boys, and 0.6 for white girls. This translates into an increase in BMI values of some 5.6, 3.3, 2.4, and 1.5 units, respectively. While the increase in BMI values started among the birth cohorts of the 1940s among black girls, the rate of increase tended to accelerate among all four ethnic/gender groups born in the mid-1950s to early-1960s. Some regional evidence leads to the conjecture that the spread of automobiles and radios affected the BMI values of boys already in the interwar period. We suppose that the changes in lifestyle associated with the labor saving technological developments of the 20th century are associated with the weight gains observed. The increased popularity of television viewing was most prominently associated with the contemporaneous acceleration in BMI gain. Am. J. Hum. Biol., 2009. © 2008 Wiley-Liss, Inc.
Read article
Growth, Volatility, and Credit Market Imperfections: Evidence from German Firms
Claudia M. Buch, Jörg Döpke
Journal of Economic Studies,
2008
Abstract
Purpose – The purpose of this paper is two-fold. First, it studies whether output volatility and growth are linked at the firm-level, using data for German firms. Second, it explores whether the link between volatility and growth depends on the degree of credit market imperfections.
Design/methodology/approach – The authors use a novel firm-level dataset provided by the Deutsche Bundesbank, the so-called Financial Statements Data Pool. The dataset has time series observations for German firms for the period 1997-2004, and the authors use information on the debt-to-assets or leverage ratio of firms to proxy for credit-constraints at the firm-level. As additional proxies for the importance of credit market imperfections, we use information on the size and on the legal status of firms.
Findings – The authors find that higher volatility has a negative impact on growth for small and a positive impact for larger firms. Higher leverage is associated with higher growth. At the same time, there is heterogeneity in the determinants of growth across firms from different sectors and across firms with a different legal status.
Practical implications – While most traditional macroeconomic models assume that growth and volatility are uncorrelated, a number of microeconomic models suggest that the two may be linked. However, it is unclear whether the link is positive or negative. The paper presents additional evidence regarding this question. Moreover, understanding whether credit market conditions affect the link between volatility and growth is of importance for policy makers since it suggests a channel through which the credit market can have long-run welfare implications. The results stress the importance of firm-level heterogeneity for the effects and effectiveness of economic policy measures.
Originality/value – The paper has two main novel features. First, it uses a novel firm-level dataset to analyze the determinants of firm-level growth. Second, it analyzes the growth-volatility nexus using firm-level data. To the best of the authors' knowledge, this is the first paper, which addresses the link between volatility, growth, and credit market imperfections using firm-level data.
Read article
