diff --git a/data/global_stocks.csv b/data/global_stocks.csv
index 69c06771186276afb2943d05d27c67aede01dff5..439a5d4764adc1a68131ed95de3bf2a2afb550cf 100644
--- a/data/global_stocks.csv
+++ b/data/global_stocks.csv
@@ -1,11 +1,12 @@
-plumCropItem,V1
-FruitVeg,182.092751337307
-WheatBarleyOats,879.537641313273
-Pulses,46.532195
-Starchy Roots,410.796684630225
-Oilcrops,378.961539547602
-MaizeMilletSorghum,810.753713560517
-Sugar,1484.01363920056
-Rice (Paddy Equivalent),439.184612481259
-Ruminants,412.1217514
-Monogastrics,45.6726812
+plumCropItem,V1
+FruitVeg,182.092751337307
+WheatBarleyOats,879.537641313273
+Pulses,46.532195
+Starchy Roots,410.796684630225
+Oilcrops,378.961539547602
+MaizeMilletSorghum,810.753713560517
+Sugar,1484.01363920056
+Rice (Paddy Equivalent),439.184612481259
+Ruminants,412.1217514
+Monogastrics,45.6726812
+Energy crops,20
\ No newline at end of file
diff --git a/src/ac/ed/lurg/InternationalMarket.java b/src/ac/ed/lurg/InternationalMarket.java
index 36e807fe416d177fd173493d97e7c7e17301fa14..d8e529197609f625248707c988a972098b063f70 100644
--- a/src/ac/ed/lurg/InternationalMarket.java
+++ b/src/ac/ed/lurg/InternationalMarket.java
@@ -69,7 +69,7 @@ public class InternationalMarket {
GlobalPrice prevPrice = worldPrices.get(crop);
double imports = totalImportCommodities.containsKey(crop) ? totalImportCommodities.get(crop) : 0.0;
double exportsBeforeTransportLosses = totalExportCommodities.containsKey(crop) ? totalExportCommodities.get(crop) : 0.0;
- LogWriter.print(timestep.getYear() + " Updating " + crop.getGamsName() + " prices : ");
+ LogWriter.println(timestep.getYear() + " Updating " + crop.getGamsName() + " prices");
GlobalPrice adjustedPrice = prevPrice.createWithUpdatedMarketPrices(imports, exportsBeforeTransportLosses, timestep, totalProduction.get(crop));
LogWriter.println( String.format("Price for %s updated from %s to %s \n", crop.getGamsName(), prevPrice, adjustedPrice));
worldPrices.put(crop, adjustedPrice);
diff --git a/src/ac/ed/lurg/country/GlobalPrice.java b/src/ac/ed/lurg/country/GlobalPrice.java
index 3848361056a0f5890b6f5c64e3d1c83c926fe2b7..310b1e4cd0b6fcdd7e6e48c7efcb1e34b9e774f3 100644
--- a/src/ac/ed/lurg/country/GlobalPrice.java
+++ b/src/ac/ed/lurg/country/GlobalPrice.java
@@ -67,50 +67,47 @@ public class GlobalPrice {
public GlobalPrice createWithUpdatedMarketPrices(double newImports, double newExportAmountBeforeLoss, Timestep timestep, double production) {
- double transportLossRate = (!ModelConfig.SHOCKS_POSSIBLE) ? ModelConfig.TRANSPORT_LOSSES : ModelConfig.getParameter(Parameter.TRANSPORT_LOSSES, timestep.getYear());
- double newTransportLosses = newExportAmountBeforeLoss * transportLossRate;
- double exportsAfterTransportLosses = newExportAmountBeforeLoss - newTransportLosses;
-
- if (newImports > 0 || exportsAfterTransportLosses > 0) {
- double oldDiff = 0;
- if (timestep.getTimestep() == timestepId) // if recomputing for same year need to back our previous adjustment
- oldDiff = exportAmountBeforeLoss - transportLosses - importAmount;
- double newDiff = newExportAmountBeforeLoss - newTransportLosses - newImports;
- double updatedStock = stockLevel + newDiff - oldDiff;
-
- LogWriter.println(String.format(" global stocks from %.2f to %.2f due to newDiff %.2f oldDiff %.2f", stockLevel, updatedStock, newDiff, oldDiff));
+ if (newImports > 0 || newExportAmountBeforeLoss > 0) {
+ double oldDiff = timestep.getTimestep() != timestepId ? 0.0 : exportAmountBeforeLoss - transportLosses - importAmount; // if recomputing for same year need to back our previous adjustment
+ double transportLossRate = (!ModelConfig.SHOCKS_POSSIBLE) ? ModelConfig.TRANSPORT_LOSSES : ModelConfig.getParameter(Parameter.TRANSPORT_LOSSES, timestep.getYear());
+ double newTransportLosses = newExportAmountBeforeLoss * transportLossRate;
+ double stockChange = newExportAmountBeforeLoss - newTransportLosses - newImports - oldDiff;
+ double updatedStock = stockLevel + stockChange;
+
+ LogWriter.println(String.format(" imports %.2f, exports %.2f", newImports, newExportAmountBeforeLoss - newTransportLosses));
+ LogWriter.println(String.format(" updatedStock %.2f, previous %.2f (last timestep %.2f), stockChange %.2f, oldDiff %.2f", updatedStock, stockLevel, stockLevel-oldDiff, stockChange, oldDiff));
if (updatedStock < 0)
LogWriter.println(String.format("Global stocks are below zero"));
- double newPrice, adjustment;
+ double adjustment;
double financialSpeculationMultiplier = (!ModelConfig.SHOCKS_POSSIBLE)? 1.0 : ModelConfig.getParameter(Parameter.FINANCIAL_SPECULATION_MULTIPLIER,timestep.getYear());
if (!ModelConfig.MARKET_ADJ_PRICE) {
adjustment = 1;
}
else if (ModelConfig.PRICE_UPDATE_BY_MARKET_IMBALANCE) {
- double ratio = (newImports-exportsAfterTransportLosses)/(newImports-exportsAfterTransportLosses+production);
- adjustment = Math.exp(ratio * ModelConfig.MARKET_LAMBA);
- LogWriter.println(String.format("Price update market imbalance: adjustment= %.4f, imports %.1f, exports %.1f", adjustment, newImports, getExportsAfterTransportLosses()));
+ double ratio = stockChange/(production-stockChange);
+ adjustment = Math.exp(-ratio * ModelConfig.MARKET_LAMBA);
+ LogWriter.println(String.format(" initally imbalance ratio= %.4f", ratio));
}
else {
- double ratio = (stockTarget - updatedStock) / stockTarget;
-
- if (ratio >= 0) {
- adjustment = 1 + ModelConfig.MARKET_LAMBA * ratio/(1 - ratio*ratio);
- if (adjustment > ModelConfig.MAX_PRICE_INCREASE || ratio > 1)
- adjustment = ModelConfig.MAX_PRICE_INCREASE; // default to max up change
- }
- else {
- adjustment = 1 / ( 1 - ModelConfig.MARKET_LAMBA * ratio/(1 - ratio*ratio));
- if (adjustment < ModelConfig.MAX_PRICE_DECREASE || ratio < -1)
- adjustment = ModelConfig.MAX_PRICE_DECREASE; // default to max down change
- }
+ if (stockChange >= 0) // stock increasing, so decrease price. stockChange is positive so adjustment < 1
+ adjustment = 1 - ModelConfig.MARKET_LAMBA * stockChange/production;
+ else // stock decreasing, so increase price. stockChange is negative so adjustment > 1
+ adjustment = 1 - ModelConfig.MARKET_LAMBA * stockChange/Math.max(0, stockLevel);
- LogWriter.println(String.format("Price update from stock target: adjustment= %.4f, ratio= %.4f", adjustment, ratio));
+ LogWriter.print(String.format(" initally adjustment= %.4f", adjustment));
}
- newPrice = exportPrice * adjustment * financialSpeculationMultiplier;
+ if (adjustment < ModelConfig.MAX_PRICE_DECREASE)
+ adjustment = ModelConfig.MAX_PRICE_DECREASE; // default to max down change
+
+ if (adjustment > ModelConfig.MAX_PRICE_INCREASE)
+ adjustment = ModelConfig.MAX_PRICE_INCREASE; // default to max up change
+
+ LogWriter.println(String.format(", after limit %.4f", adjustment));
+
+ double newPrice = exportPrice * adjustment * financialSpeculationMultiplier;
return new GlobalPrice(timestep.getTimestep(), newPrice, updatedStock, stockTarget, newImports, newExportAmountBeforeLoss, newTransportLosses);
}
else {
@@ -127,5 +124,4 @@ public class GlobalPrice {
public double getStockChange() {
return exportAmountBeforeLoss - transportLosses - importAmount;
}
-}
-
+}
\ No newline at end of file