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10. Trade data come from the BOP Unit of the Ministry of Finance. Because<sup>this data comes</sup> from the same source as the balance of payments figures,<sup>they are expected to be consistent. The</sup> trade table provides information on major items in the merchandise<sup>account, including export earnings</sup> of coffee, tea, petroleum, horticulture and manufactured goods as well as<sup>imports of</sup> food, petroleum, primary intermediate goods, manufacturing intermediate<sup>g&. Is and capital goods.</sup> These items serve as the basis for projecting the trade account.

11. Apart from ensuring that columns add up correctly, the model checks for consistency<sup>between</sup> stocks and flows within given worksheets, and identifies inconsistencies aross data input<sup>sheets. For</sup> example, it checks for consistency between the capital flows implied by the<sup>DRS debt data, the</sup> balance of payments, the fiscal accounts and the monetary accounts, and calculates<sup>the adjustments</sup> which are required for consistency between capital and current sources<sup>and uses of funds. Similar</sup> calculations are done after trade data in the nadonal accounts are compared<sup>with the figures in the</sup> balance of payments. Because the national accounts are viewed as the 'umbrella,'<sup>the rule of thumb</sup> is to identify those adjustments which make the input tables internally consistent, reconcile stocks with flows and achieve intersectoral consistency in relation to the national accounts.<sup>The model</sup> specifies these adjustments explicitly.

# Updating Historical Data

12. The model has been designed so that in general, historical data entered<sup>in the data input</sup> worksheets automatically override projected data. The task of updating the model is simply<sup>one of</sup> entering the most recent year's data in the appropriate data entry worksheet.<sup>For example, the</sup> national accounts projected by the model for 1990 could be replaced by the actuals for 1990 when they are entered in the national accounts data entry worksheet. If similar<sup>data is not available</sup> for monetary aggregates or other sectors, the model would continue to apply the<sup>projection rules for</sup> years (including 1990) for which historical data are available. However, the projections<sup>would now</sup> be consistent with national accounts information for 1990.

13. Exceptions to this simple rule for updating the model are projected variables<sup>which use</sup> historical input data for explicidy specified years Mn are programmed to<sup>apply from a given starting</sup> date. Many of these formulae and their calculated variables are time-bound<sup>to avoid simultaneity</sup> which JAVELIN is unable to handle or to anchor the base year of an<sup>index.</sup><sup>_Thetime-bound_</sup> _formulae are presented in Annex V._

# Programming Information

14. The model is programmed in JAVELIN, a spreadsheet and database<sup>management software</sup> package. The program solves the model recursively, subject to the convergence<sup>criteria which the</sup> user of the model could change easily. The solutions reported in this paper<sup>satisfy the criterion of</sup> falling within -5 and 5 units of the target.

15. A 'macro' has been written for each of the solutions discussed<sup>in Chapters mand IV:</sup> exchange rate solution, interest rate solution, monetization, exchange<sup>rate and interest rate solution,</sup> and the exchange rate, interest rate and monetization solution. Each<sup>of these macros operates</sup> sequendally from 1990 through 1996. For flexibility, additional macros<sup>have been written which</sup> activate each of the foregoing solutions one year at a time.