An Econometric Model of CGE Simulations

CGE models are widely used tools for economic assessments of trade policy changes. However, overall confidence in their results tends to be low. We employ the methodological framework of meta-analysis in order to approach a quantitative comparison of CGE-based simulation results. Therefore, we compile a dataset of twelve recent Doha simulations and fit a linear regression model that explains the variance between simulation results on the regional level as a function of various modeling characteristics. The estimates are broadly in range with documented qualitative knowledge about modeling assumptions. The size of the sample limits general conclusions; however, an ongoing research project will extend the approach to a larger sample.CGE, systematic review, Doha round, evaluation, Research Methods/ Statistical Methods, C20, C68, D58, F10, C99,

Irrationality or efficiency of macroeconomic survey forecasts? Implications from the anchoring bias test

We analyze the quality of macroeconomic survey forecasts. Recent findings indicate that they are anchoring biased. This irrationality would challenge the results of a wide range of empirical studies, e.g., in asset pricing, volatility clustering or market liquidity, which rely on survey data to capture market participants' expectations. We contribute to the existing literature in two ways. First, we show that the cognitive bias is a statistical artifact. Despite highly significant anchoring coefficients a bias adjustment does not improve forecasts' quality. To explain this counterintuitive result we take a closer look at macroeconomic analysts' information processing abilities. We find that analysts benefit from the use of an extensive information set, neglected in the anchoring bias test. Exactly this information advantage drives the misleading anchoring bias test results. Second, we find that the superior information aggregation capabilities enable analysts to easily outperform sophisticated timeseries forecasts and therefore survey forecasts should clearly be favored. --macroeconomic announcements,efficiency of forecasts,anchoring bias,rationality of analysts

Meta Response Surface Design for General and Partial Equilibrium Models

Due to the complexity of general and partial equilibrium models, conventional sensitivity analysis, qualitative reviews or literature-based meta-analyses do not allow for detailed assessments of the role of individual parameters and policy shocks across different models. Therefore, the partial equilibrium model “GSIM” and a single country CGE are employed to generate synthetic scenarios based on randomly specified combinations of base data, elasticities and tariff changes selected from previously specified, plausible ranges. The synthetic meta-data has the advantage that the values of explanatory variables are measured exactly. This makes it possible to explore complex issues of functional form and interaction between variables in the estimation of the response surface of each model as well as for a joint response surface of both models. The results indicate that firstand second-order polynomials provide sufficient approximations of the model responses, and especially for the CGE model, interaction terms of elasticities with policy variables play an important role. Furthermore, simultaneous estimation of a response surface of scenarios from both models proves to be feasible and enables quantitative comparisons of different model output, e.g. welfare measures.General Equilibrium, Partial Equilibrium, Response Surface Design, Research Methods/ Statistical Methods,

Meta-Analysis of General and Partial Equilibrium Simulations of Doha Round Outcomes

Quantification of welfare changes due to trade liberalisation play a crucial role for political decision making. However, meaningful comparisons of simulation results from different sources are difficult. Often significant differences in simulated gains from liberalisation do not serve to increase confidence in quantitative assessments based on trade models. We employ a metaanalysis of applied trade simulations under the WTO Doha Round to identify model characteristics that influence the magnitude of simulation results, and to estimate the magnitude of this influence. Findings from our simple econometric model are plausible and show that each simulation experiment represents a complex interaction of experimental settings that may not easily be understood by and communicated to non-experts. Meta-analysis proves to be a useful tool for empirically assessing this complexity.Meta-analysis, CGE, Partial Equilibrium, Trade Liberalization, C00, C23, C68, F10, International Relations/Trade,

"Feed the Mouth, the Eye Ashamed": Have Food Prices Triggered Social Unrest in Egypt?

A monthly panel dataset was used to empirically examine the role of food prices in the emergence of social unrest in various geographic regions of Egypt between 1998 and 2013. A media discourse analysis traced reports in two leading Egyptian newspapers about social unrest, overall dissatisfaction with the government, and food price inflation. A fixed effects binary logit panel model has found that the probability of social unrest is statistically related to macroeconomic control variables such as domestic and global food prices, and GDP per capita. Higher temperatures were associated with an increased likelihood of social unrest through their influences on food production and yields, and price volatility in domestic food markets. In addition, the results support to the hypothesis that social unrest in developing countries has a strong "spatial" dimension, where urban dwellers were found to have a greater capacity to engage in collective action leading to social unrest. Finally, media reports about food price inflation were also statistically related to the occurrence of social unrest; but the estimated effect of overall dissatisfaction with institutional quality is even higher. Overall, the results suggest that soaring food prices, despite significant, were unlikely the single most important reason for social unrest in Egypt

The Swedish Media Debate on GMO Between 1994 and 2018: What Attention was Given to Farmers' Perspectives?

This paper presents a longitudinal study of the debate on GMO in the Swedish media, comparing coverage of the topic in the general press and agricultural press. We studied 1399 articles about GMO in food and agriculture published between 1994 and 2018 in Sweden's daily and evening newspapers and agricultural publications. A combination of content analysis and statistical simulation techniques was used to identify structural breaks in the dataset and contribute understanding about how the debate shifted over time. Particular attention was paid to issues of importance to farmers in the Swedish media discourse. Our findings indicate that the debate was most intense in the mid-1990s, after which the frequency of reporting on GMOs declined overall and the debate steadily became less negative. Farmers' perspectives were given more attention than expected in the general media but, surprisingly, smallholder farming and food security in the Global South, which has been central to global and elite debates on GMO, did not appear to substantially affect media discourses in Sweden

Consumers’ Willingness to Pay for Food Safety in Nairobi: The Case of Fresh Vegetables

Large urban areas in developing countries represent currently the most dynamically growing markets for food products. This study investigates the willingness to pay of consumers in Nairobi for safer leafy vegetables. We survey individuals’ perceived food safety across four major market categories, while also considering the explanatory role of trust and behavioral, psychological, and socio-demographic covariates. Results show that willingness to pay is market-specific and multi-faceted, with trust and perceived risks as important drivers, while income plays only a subordinate role. We conclude that policy makers should aim to reduce asymmetric information within the value chain without raising food prices such that safer vegetables would become unaffordable for the poor.Food safety, perceived risk, willingness to pay, regression tree, urban agriculture, Crop Production/Industries, Food Consumption/Nutrition/Food Safety,

Thermodynamic and mesoscopic modeling of tumbling nematics, of shear-thickening fluids and of stick-slip-like flow behavior

Shear thickening, i.e. the increase of the viscosity with increasing shear rate as it occurs in dense colloidal dispersions and polymeric fluids is an intriguing phenomenon with a considerable potential for technical applications. The theoretical description of this phenomenon is patterned after the thermodynamic and mesoscopic modeling of the orientational dynamics and the flow behavior of liquid crystals in the isotropic and nematic phases, where the theoretical basis is well-established. Even there the solutions of the relevant equations recently yielded surprises: not only stable flow alignment and a periodic behavior (tumbling) are found as response to an imposed stationary shear flow but also irregular and chaotic dynamics occurs for certain parameter ranges. To treat shear-thickening fluids, a non-linear Maxwell model equation for the symmetric traceless part of the stress tensor has been proposed in analogy to the equations obeyed by the alignment tensor of nematics. The fluid-solid transition is formally analogous to the isotropic-nematic transition. In addition to shear-thickening and shear-thinning fluids, substances with yield stress can be modeled. Furthermore, periodic stick-slip-like motions and also chaotic behavior are found. In the latter cases, the instantaneous entropy production is not always positive. Yet it is comforting that its long-time average is in accord with the second law