A user-friendly front-end for Eviews- based macro-structural models MFMSA: A user-friendly front-end for Eviews- based macro-structural models Andrew Burns World Bank October 4, 2017 a aburns@worldbank.org

World Bank Modelling Environment World bank uses a wide range of models Global models MFMod Macrostructural model used for forecasting and simulation Dynamic recursive CGE models (Envisage III; Manage) Country specific models Usually adapted and customized from global models MFMod (Macro-Fiscal model) built specifically to allow collaborative forecasting with and easy-to-use interface MFModSA (MFMod Stand Alone) adapted from MFMod Easy-to-use front end for forecasting and simple simulation Access to Eviews object module for more complicated work and reporting Highly customizable

The modelling challenge at the World Bank Need to forecast 180+ countries 4 times a year Significant country expertise embedded in 300+ country economists the vast majority of whom are field based Disparate modelling skills within country-economist community

Solution – MFMod internet-based model Produce a low-cost, easy-to-use forecasting system that can be used by economists with different technical backgrounds sitting in 100+ locations Both a global model and 180+ country models Country models can be solved independently of global model, using isimulate collaborative forecasting platform (isimulate.worldbank.org)

Limitations of MFMod system Country models are, of necessarily, partially standardized Share common structure and functional forms, with parameters estimated to fit country data Some 40 different variants (oil exporting; fixed exchange rate economies; economies with and without production accounts etc.) Lack institutional / fiscal detail that a fully-blown customized country model would have Separate accounting of major commodity sector (other than oil) Detailed mapping of country-specific fiscal features Limited ability to customize equations, functional forms etc

MFMod Stand Alone Combines benefits of MFMod system but allows for the customization that main internal bank-wide system lacks COM-based Excel / EViews implementation of MFMod user interface Highly customizable (layout, reports) model content Main vocation is to run a single country model, typically a customized version of the internet-based MFMod – with additional fiscal and sectoral detail and or longer time period (but platform is agnostic on model / use)

Principle advantages of MFMod SA Highly Customizable Increased fiscal, structural, financial detail to meet client needs Annual, Quarterly or Monthly models One or two “model Mechanics” can be trained to maintain, modify and customize Easy-to-operate Model drivers do not need “modeler skills” Interface allows a flexible interaction with model without any programming Ability to save and compare multiple scenarios Easy access to EViews back end to prepare customized reports (very powerful) Flexibility means unlimited potential uses Forecasting Medium-term budgetary analysis Tax policy analysis External shocks Alternative policy scenarios Complex mixture of excel, .NET, MySQL, PHP, and EViews code Excel and .NET manage the user interface, MYSQL and PHP, a middle-ware, which interprets inputs from excel and writes eviews scripts reflecting user inputs Middleware module looks after record keeping, and allows for user to go backwards and forwards through the simulation history (random access Undo / Redo functionality) model is written and solves in eviews

Interface hides the model MFModSA uses excel as front-end with EViews operating as solution engine EViews and Excel Middleware controls Dot net User with excel front-end Excelified changes Excelified results EViews Code EViews description of simulation Results of EViews simul

Middleware manages user’s interactions with EViews model MFMod SA EViews back end Excel front end Middleware Writes and executes Eviews simulation based on Excel inputs Returns results and allows visualization/ comparison of results All data are stored and calculations done in EViews

A clean and consistent interface

Clean and consistent interface Model is broken up into economically meaningful sheets / blocks

Clean and consistent interface Endogenous Exogenous Identity (closure rule) Historical Data distinguishes Color coding between qualities of variables

Clean and consistent interface Data display can be changed from growth rates, levels % GDP, or contribution to growth by selecting from the drop down

Clean and consistent interface The change Display mode button changes the representation of all the series on the sheet

Model suggestion in black The display options Equation triplet User in red Model suggestion in black Add-factor in blue

The display options: Viewing equations Right click on variable name and select View equation

The model is operated via the menu 1 2 3 4 5 6 7 8 9 10 Load the EViews work file Save the EViews work file Solve the model Make model endogenous or exogenous – controls the sheets Display variables in levels, growth rates, ratios or contribution to GDP Compare policy shocks or alternative forecasts Set the model parameters Set type of growth rate for quarterly models About and news on the standalone A help file for specific issues