AGRODEP

A dynamic multi-country, multi-sector general equilibrium model. The dynamics is recursive and the model is calibrated on the GTAP database. MIRAGRODEP is a new version of the MIRAGE model of the world economy, whose GAMS code has been simplified and presented in a more compact and user-friendly way. More information about the model is available here. Download MIRAGRODEP 1.0 model code and documentation (version 1.0). Documentation are also available for the MIRAGRODEP Dual-Dual, MIRAGRODEP-AEZ, MIRAGRODEP with endogenous tariffs, and MIRAGRODEP 2.0 models.

Different from many single-commodity partial equilibrium models, the Export Restrictions And import Tariffs Overall impacts (ERATO) model illustrates how a multi-market model can be used to analyze trade policy options in a context of a multi-product value chain. It can also be used to study different productivity shock or tax changes in a sectoral value chain. The documentation describes the theory and the GAMS code developed to implement this global multimarket partial equilibrium model where three stages of the oilseed production are considered: (i) production of seeds, (ii) production of meals and oils, (iii) production of biodiesel. Download ERATO model code and documentation.

PETS is a multi-region, multi-sector, dynamically recursive, and partial equilibrium (PE) model. The model, developed in Fontagne, Laborde, and Mitaritonna (2011), focuses on trade policy analysis using disaggregated geographical and sectoral levels of data. The model emphasizes the demand side, which is specified as a nested CES structure, where the initial regional income is assumed to be fixed. The demand is expressed at various levels of disaggregation matched by increasing substitutability (elasticity of substitution increases with higher level of disaggregation). Download the model code and the documentation.

The Partial Equilibrium Trade (PE-TRADE) model which is set up in Excel can be used for analyzing the implications of various trade policies and providing support to the trade negotiators at a detailed level. Although it has limitations in terms of its coverage of the economy, the PE-TRADE model is flexible enough to respond to changes in trade policy scenarios quickly and provide “first order” effects promptly (with room to allow incorporation of local knowledge from domestic policy sources). Download the model code and the documentation.

The spatial equilibrium model is a multi-region partial equilibrium model which links producers and consumers from different locations. It allows economists to examine the global economic and trade consequences of diverse trade policies by determining their effects on market, trade and welfare variables. It evaluates the impact of such policies on supply and demand, producer and consumer prices, volume and direction of trade, consumer and producer surpluses, as well as on world welfare. Download model code (EN|FR) and the documentation in English and in French.

The model codes provided in the toolbox provides several examples of hands-on estimation with gravity equation methodological choices highlighted in the literature review in the accompanying documentation. An illustrative dataset with alternative Stata codes presents the different possible estimation strategies. The user can use STATA to carry out estimations to become familiar with the software and the gravity model. Download model toolbox and the documentation about the gravity model and documentation about the model toolbox.

As discussed in Laborde, Martin, and van der Mensbrugghe (2011), using an optimal tariff aggregator to perform trade policy simulations is critical to improving quantitative assessments of trade reform. Nevertheless, providing such inputs for general and partial equilibrium models can be cumbersome since it requires combining large datasets (several millions of trade flows and tariffs for a given year at a global level), a set of parameters (elasticities of substitution) and mathematical programming of the functional forms used in the disaggregated part of the approach. To help potential users, the toolbox provides a set of tools allowing users to reproduce the results discussed in Laborde, Martin, and van der Mensbrugghe (2011) and to perform their own aggregation and tariff reduction scenarios. Download the toolbox and the documentation.

The AGRODEP GAMS Training Toolbox is intended to assist those interested in economic modeling– including but not limited to general and partial equilibrium models as well as optimization problems– by teaching them to use the GAMS software, a cornerstone of many modeling efforts. These economic models can be used to conduct research on a wide range of topics, such as analysis of various forms of policies, issues pertaining to agricultural growth and poverty, climate change, natural resource management, and the role of science and technology. In the course of ten video lessons, available with English or French voiceovers, and multiple GAMS code examples, the user will gradually learn the GAMS language from the basic installation instructions to the more sophisticated GAMS syntax and programming techniques, ending with an introduction to economic modeling. YouTube training videos are available in English and in French. Download codes for Lesson 2, Lesson 4, Lesson 5, Lesson 6, Lesson 7, Lesson 8, Lesson 9, and Lesson 10.

Development of agricultural value chains is necessary to help smallholder farmers in Africa. Domestic agricultural policies and trade policies impact all economic agents along the value chain, from farmers to traders to consumers. Thus, it is critical to understand the impact of policy distortions to agricultural incentives along the complete value chain. The AGRODEP Incentives along Value Chains (IVC) Toolbox in Excel was developed to aid AGRODEP researchers in conducting this type of analysis on distortions in the value chain with a focus on agriculture. Download the toolbox and the documentation.

This macroeconometric modelling toolbox allow users to build their own models. The presentation is complemented by examples using the EViews software, from general strategies to technical details. The associated programs and files are provided. It is focused on Africa and presents the specific issues, problems and strategies for modeling this region and developing countries in general. Download the toolbox and the documentation.

The toolbox allows users to explore the sensitivity of computable general equilibrium (CGE) models to the choice of macroeconomic closure rules using the case of the standard IFPRI model for Nigeria and Tanzania. Two sets of simulations are performed: a 50 percent decrease in import taxes and a 10 percent increase in agricultural productivity. For each simulated scenario, around 10 closure rules related to the government, the rest of the world, the investment-savings equilibrium, and the factors market are examined. Download the toolbox and the documentation.

The toolbox contains the codes used to run microsimulations linked to CGE models. As a specific example, it uses the IFPRI standard CGE model and the Tanzania Household Budget Survey 2000/2001 to simulate a 50% fall in export prices in Tanzania. Two microsimulation techniques are implemented: a non-parametric microsimulation model and a representative household model. Download the toolbox and the documentation.

Variants of rational expectations storage models are central to neoclassical studies of the behavior of markets for storable commodities. Like most dynamic stochastic problems, this model cannot be solved analytically. The lack of user-friendly software to solve storage models in the past may have represented a serious barrier to entry for research on these issues. The RECS toolbox provides a modeling environment allowing economists to focus on the economic problem at hand, while abstracting from various issues related to the numerical implementation. Download the toolbox and the documentation.

The toolbox provides methods for updating and balancing Social Accounting Matrices (SAMs) using Rwanda SAMs from 2006 and 2011 as an example. The objective is to update the initial SAM (2006) using four separate methods and compare each updated SAM with the final or observed SAM (2011). The four methods explored are Cross-Entropy, Ordinary Least Squares, Huber, and Hellinger methods. The accompanying documentation further details about each method, and walks users through the comparison process. Download toolbox and documentation.

The toolbox provides a technical guide, Stata code, and data files to estimate supply and demand elasticities. The first portion of the guide is dedicated to the estimation of elasticities in producer theory and portion two is dedicated to elasticities in consumer theory. Download toolbox and documentation.