diff --git a/src/ac/ed/lurg/InternationalMarket.java b/src/ac/ed/lurg/InternationalMarket.java
index 69788430c3f057cc19024bad161586a1ccd57b2f..36d9bd57207ed673059a67a20f004c7b32565f8e 100644
--- a/src/ac/ed/lurg/InternationalMarket.java
+++ b/src/ac/ed/lurg/InternationalMarket.java
@@ -169,7 +169,7 @@ public class InternationalMarket {
GlobalPrice prevCPrice = carbonPrice;
LogWriter.println(timestep.getYear() + " Updating carbon price", 2);
GlobalPrice adjustedCPrice = prevCPrice.createWithUpdatedMarketPrices(totalCarbonImport, totalCarbonExport, timestep,
- totalCarbonSequestered, false, 0.2);
+ totalCarbonSequestered, false, ModelConfig.DEFAULT_STOCK_USE_RATIO);
LogWriter.println( String.format("Price for carbon updated from %s to %s \n", prevCPrice, adjustedCPrice), 2);
if (adjustedCPrice.getStockLevel() < 0)
LogWriter.println("Global stocks are below zero carbon, " + timestep.getYear(), 2);
@@ -195,7 +195,7 @@ public class InternationalMarket {
GlobalPrice prevTPrice = woodPrices.get(woodType);
LogWriter.println(timestep.getYear() + " Updating " + woodType.getName() + " price", 2);
GlobalPrice adjustedTPrice = prevTPrice.createWithUpdatedMarketPrices(totalWoodImport, totalWoodExport,
- timestep, totalWoodProduction, true, 0.2);
+ timestep, totalWoodProduction, true, ModelConfig.DEFAULT_STOCK_USE_RATIO);
LogWriter.println( String.format("Price for wood updated from %s to %s \n", prevTPrice, adjustedTPrice), 2);
if (adjustedTPrice.getStockLevel() < 0)
LogWriter.println("Global stocks are below zero wood, " + timestep.getYear(), 2);
diff --git a/src/ac/ed/lurg/ModelConfig.java b/src/ac/ed/lurg/ModelConfig.java
index 51f8d80ca045e206f4947eec9459d10c8892e19b..9de22fae3b4e41a62783797a1ead49c3235d2e0d 100755
--- a/src/ac/ed/lurg/ModelConfig.java
+++ b/src/ac/ed/lurg/ModelConfig.java
@@ -363,9 +363,9 @@ public class ModelConfig {
public static final int BASE_YEAR = getIntProperty("BASE_YEAR", 2019);
// Import export limits
- public static final double ANNUAL_MAX_IMPORT_CHANGE = getDoubleProperty("ANNUAL_MAX_IMPORT_CHANGE", 0.5);
+ public static final double ANNUAL_MAX_IMPORT_CHANGE = getDoubleProperty("ANNUAL_MAX_IMPORT_CHANGE", 1.0); // Loose constraint as we have TRADE_ADJUSTMENT_COST_RATE
public static final double MAX_IMPORT_CHANGE = getDoubleProperty("MAX_IMPORT_CHANGE", ANNUAL_MAX_IMPORT_CHANGE*TIMESTEP_SIZE);
- public static final double TRADE_ADJUSTMENT_COST_RATE = getDoubleProperty("TRADE_ADJUSTMENT_COST_RATE", 0.02);
+ public static final double TRADE_ADJUSTMENT_COST_RATE = getDoubleProperty("TRADE_ADJUSTMENT_COST_RATE", 0.01);
// Price caps
public static final String PRICE_CAP_FILE = DATA_DIR + File.separator + "price_caps.csv";
@@ -404,10 +404,10 @@ public class ModelConfig {
public static final String CONVERSION_COST_FILE = getProperty("CONVERSION_COST_FILE", DATA_DIR + File.separator + "conversion_costs.csv"); // cost of converting from one land cover to another, $1000/ha
public static final double LAND_CONVERSION_COST_FACTOR = getDoubleProperty("LAND_CONVERSION_COST_FACTOR", 1.0); // for monte carlo
public static final double AGRI_LAND_EXPANSION_COST_FACTOR = getDoubleProperty("AGRI_LAND_EXPANSION_COST_FACTOR", 1.0); // for monte carlo
- public static final double CROPLAND_CONVERSION_COST = getDoubleProperty("CROPLAND_CONVERSION_COST", 0.11 * LAND_CONVERSION_COST_FACTOR);
- public static final double PASTURE_CONVERSION_COST = getDoubleProperty("PASTURE_CONVERSION_COST", 0.08 * LAND_CONVERSION_COST_FACTOR);
- public static final double FOREST_CONVERSION_COST = getDoubleProperty("FOREST_CONVERSION_COST", 0.1 * LAND_CONVERSION_COST_FACTOR);
- public static final double NATURAL_CONVERSION_COST = getDoubleProperty("NATURAL_CONVERSION_COST", 0.015 * LAND_CONVERSION_COST_FACTOR);
+ public static final double CROPLAND_CONVERSION_COST = getDoubleProperty("CROPLAND_CONVERSION_COST", 0.30 * LAND_CONVERSION_COST_FACTOR);
+ public static final double PASTURE_CONVERSION_COST = getDoubleProperty("PASTURE_CONVERSION_COST", 0.20 * LAND_CONVERSION_COST_FACTOR);
+ public static final double FOREST_CONVERSION_COST = getDoubleProperty("FOREST_CONVERSION_COST", 0.50 * LAND_CONVERSION_COST_FACTOR);
+ public static final double NATURAL_CONVERSION_COST = getDoubleProperty("NATURAL_CONVERSION_COST", 0.01 * LAND_CONVERSION_COST_FACTOR);
public static final double TECHNOLOGY_CHANGE_ANNUAL_RATE = getDoubleProperty("TECHNOLOGY_CHANGE_ANNUAL_RATE", 0.002);
public static final int TECHNOLOGY_CHANGE_START_STEP = getIntProperty("TECHNOLOGY_CHANGE_START_STEP", 0);
@@ -425,10 +425,12 @@ public class ModelConfig {
public static final boolean RESET_ENERGYCROP_PRICE = getBooleanProperty("RESET_ENERGYCROP_PRICE", true); // Resets price after calibration to avoid problems due to low initial demand
// public static final double BIOENERGY_HEATING_VALUE_GJ_PER_T = getDoubleProperty("BIOENERGY_HEATING_VALUE_GJ_PER_T", 17.5); // GJ per t DM
- public static final double MARKET_BETA = getDoubleProperty("MARKET_BETA", 0.015); // controls international market price adjustment rate
public static final double MARKET_LAMBDA = getDoubleProperty("MARKET_LAMBDA", 0.4); // controls international market price adjustment rate
+ public static final double EXPORT_ADJUSTMENT_RATE = getDoubleProperty("EXPORT_ADJUSTMENT_RATE", 1.0); // Tries to guide export levels towards import levels
+ public static final double STOCK_ADJUSTMENT_RATE = getDoubleProperty("STOCK_ADJUSTMENT_RATE", 0.1); // Tries to guide stock levels towards target level
+ public static final double DEFAULT_STOCK_USE_RATIO = getDoubleProperty("DEFAULT_STOCK_USE_RATIO", 0.2);
- public static final String PRICE_UPDATE_METHOD = getProperty("PRICE_UPDATE_METHOD", "StockUseRatio"); // Options: StockUseRatio, MarketImbalance, StockChange
+ public static final String PRICE_UPDATE_METHOD = getProperty("PRICE_UPDATE_METHOD", "StockFlow"); // Options: StockFlow, MarketImbalance, StockChange
public static final double MAX_PRICE_INCREASE = getDoubleProperty("MAX_PRICE_INCREASE", 1.5);
public static final double MAX_PRICE_DECREASE = getDoubleProperty("MAX_PRICE_DECREASE", .75);
public static final int DEMAND_RECALC_MAX_ITERATIONS = IS_CALIBRATION_RUN ? 0 : getIntProperty("DEMAND_RECALC_MAX_ITERATIONS", 0); // 0 is original behaviour
diff --git a/src/ac/ed/lurg/country/CountryAgent.java b/src/ac/ed/lurg/country/CountryAgent.java
index f870f4319d178335171216ec2eefabfb2eb77603..728939e7932c883a2f8e1574f48f203fe26cfb88 100644
--- a/src/ac/ed/lurg/country/CountryAgent.java
+++ b/src/ac/ed/lurg/country/CountryAgent.java
@@ -165,9 +165,8 @@ public class CountryAgent extends AbstractCountryAgent {
CropUsageData cropUsage = entry.getValue();
CropType crop = entry.getKey();
double baseTrade = cropUsage.getNetImportsExpected();
- double changeUp = 0;
- double changeDown = 0;
-
+ double changeUp, changeDown;
+
// max of supply overall, needed for when imports are supplying feed and change is zero to allow for production to replace imports
// minimum 1 so trade balance can still change when supply is 0
double maxOfProdOrSupply = Math.max(cropUsage.getProductionExpected() + Math.max(baseTrade, 0), 1);
@@ -177,6 +176,20 @@ public class CountryAgent extends AbstractCountryAgent {
} else {
changeDown = changeUp = maxOfProdOrSupply * ModelConfig.MAX_IMPORT_CHANGE;
}
+
+ if (crop.isImportedCrop()) {
+ // Guide export level towards import level
+ if (baseTrade < 0) {
+ double ratio = currentWorldPrices.get(crop).getExportAdjustment(crop.getStockToUseRatio());
+ baseTrade *= ratio;
+ cropUsage.updateNetImports(cropUsage.getNetImportsExpected() * ratio);
+ }
+
+ // If stock about to go negative temporarily increase import price
+ if (currentWorldPrices.get(crop).isStockCritical()) {
+ currentCountryPrices.get(crop).adjustImportPrice(2.0);
+ }
+ }
if (CropType.ENERGY_CROPS.equals(crop) && baseTrade == 0) { // could apply this logic for all crops?
changeDown = changeUp = ModelConfig.MAX_IMPORT_CHANGE * currentGen2EcDemand;
@@ -207,17 +220,29 @@ public class CountryAgent extends AbstractCountryAgent {
if (ModelConfig.IS_CARBON_ON) {
double baseTrade = carbonUsageData.getNetCarbonImport();
- double changeUp = 0.0;
- double changeDown = 0.0;
+ double changeUp, changeDown;
+
if (Math.abs(baseTrade) < 1e-3) { // to set initial trade when starting from zero
changeUp = changeDown = getCurrentCarbonDemand();
} else {
double maxOfProdOrSupply = Math.max(carbonUsageData.getCarbonCredits() + Math.max(baseTrade, 0), 1);
- // double change otherwise we run into issues as not all countries can meet demand with domestic production
changeUp = changeDown = maxOfProdOrSupply * ModelConfig.MAX_IMPORT_CHANGE;
}
+ // Guide export level towards import level
+ if (baseTrade < 0) {
+ double ratio = globalCarbonPrice.getExportAdjustment(ModelConfig.DEFAULT_STOCK_USE_RATIO);
+ baseTrade *= ratio;
+ carbonUsageData.updateNetImports(carbonUsageData.getNetCarbonImport() * ratio);
+ }
+
+ // If stock about to go negative temporarily increase import price
+ if (globalCarbonPrice.isStockCritical()) {
+ currentCarbonPrice.adjustImportPrice(2.0);
+ }
+
carbonTradeConstraint = new TradeConstraint(baseTrade - changeDown, baseTrade + changeUp);
+
} else {
carbonTradeConstraint = new TradeConstraint(0, 0);
}
@@ -246,6 +271,18 @@ public class CountryAgent extends AbstractCountryAgent {
changeUp = changeDown = maxOfProdOrSupply * ModelConfig.MAX_IMPORT_CHANGE;
}
+ // Guide export level towards import level
+ if (baseTrade < 0) {
+ double ratio = globalWoodPrices.get(woodType).getExportAdjustment(ModelConfig.DEFAULT_STOCK_USE_RATIO);
+ baseTrade *= ratio;
+ woodUsageData.get(woodType).updateNetImports(woodUsageData.get(woodType).getNetImport() * ratio);
+ }
+
+ // If stock about to go negative temporarily increase import price
+ if (globalWoodPrices.get(woodType).isStockCritical()) {
+ currentWoodPrices.get(woodType).adjustImportPrice(2.0);
+ }
+
woodTradeConstraints.put(woodType, new TradeConstraint(baseTrade - changeDown, baseTrade + changeUp));
}
diff --git a/src/ac/ed/lurg/country/CountryPrice.java b/src/ac/ed/lurg/country/CountryPrice.java
index 96590b50d5ac283fe556d5c1f281118a594ef4e7..bdd1b027c8e9f6f27e981576fb383f9bc27acbc9 100644
--- a/src/ac/ed/lurg/country/CountryPrice.java
+++ b/src/ac/ed/lurg/country/CountryPrice.java
@@ -87,6 +87,10 @@ public class CountryPrice {
else
return getExportPrice();
}
+
+ public void adjustImportPrice(double factor) {
+ importPrice *= factor;
+ }
@Override
public String toString() {
diff --git a/src/ac/ed/lurg/country/GlobalPrice.java b/src/ac/ed/lurg/country/GlobalPrice.java
index fa1ea9f57e4d6058e0f6a6efa6263a865ecbe794..84256e7c5ead43aa42eaa86b1afcfe4a2fc5b674 100644
--- a/src/ac/ed/lurg/country/GlobalPrice.java
+++ b/src/ac/ed/lurg/country/GlobalPrice.java
@@ -100,21 +100,14 @@ public class GlobalPrice implements Serializable {
if (!ModelConfig.MARKET_ADJ_PRICE || (ModelConfig.IS_CALIBRATION_RUN && thisTimeStep.getTimestep() <= ModelConfig.END_FIRST_STAGE_CALIBRATION)) {
adjustment = 1;
}
- else if (ModelConfig.PRICE_UPDATE_METHOD.equals("StockUseRatio")) {
- // MARKET_BETA controls how strongly prices adjust to stock imbalance
- // MARKET_LAMBDA controls how quickly prices reach equilibrium
- //adjustment = 1 - (ModelConfig.MARKET_BETA * (updatedStock - targetStock) + ModelConfig.MARKET_LAMBDA * stockChange) / production;
+ else if (ModelConfig.PRICE_UPDATE_METHOD.equals("StockFlow")) {
// Sum of target stock and trade flow volume. Trying to avoid large swings in prices when stocks low
double stockAndFlow = stockLevel + Math.max(newImports, newExportAmountBeforeLoss);
- adjustment = 1 - (ModelConfig.MARKET_LAMBDA * stockChange / stockAndFlow
- + ModelConfig.MARKET_LAMBDA * (stockChange - prevStockChange) / stockAndFlow
- + ModelConfig.MARKET_BETA * (updatedStock - targetStock) / targetStock );
-
- // Maximum price increase if projected stock below zero
- if (updatedStock + stockChange + (stockChange - prevStockChange) <= 0) {
- adjustment = ModelConfig.MAX_PRICE_INCREASE;
- }
+ // (1) stockChange analogous to velocity of change
+ // (2) (stockChange - prevStockChange) analogous to acceleration of change
+ // We need (2) to avoid large changes in prices when trade imbalance is already reducing
+ adjustment = 1 - ModelConfig.MARKET_LAMBDA * (stockChange + 0.5 * (stockChange - prevStockChange)) / stockAndFlow;
}
else if (ModelConfig.PRICE_UPDATE_METHOD.equals("MarketImbalance")) {
double ratio = stockChange/(production-stockChange);
@@ -177,5 +170,17 @@ public class GlobalPrice implements Serializable {
this.stockLevel = stock;
}
+ public boolean isStockCritical() { // is stock projected to go below 0?
+ double stockChange = exportAmountBeforeLoss - transportLosses - importAmount;
+ return stockLevel + stockChange + (stockChange - prevStockChange) <= 0;
+ }
+
+ public double getExportAdjustment(double targetStockUseRatio) {
+ double surplus = stockLevel - (stockLevel / stockUseRatio) * targetStockUseRatio;
+ double ratio = importAmount / (ModelConfig.EXPORT_ADJUSTMENT_RATE * exportAmountBeforeLoss
+ + ModelConfig.STOCK_ADJUSTMENT_RATE * surplus);
+ return ratio;
+ }
+
}
\ No newline at end of file
diff --git a/src/ac/ed/lurg/country/gams/GamsLocationOptimiser.java b/src/ac/ed/lurg/country/gams/GamsLocationOptimiser.java
index 99f5c442cb91be783ed3c5c9c60669ae1afb8255..b802bd3a07ca38e72fe252f69cb4e7fced6251cf 100644
--- a/src/ac/ed/lurg/country/gams/GamsLocationOptimiser.java
+++ b/src/ac/ed/lurg/country/gams/GamsLocationOptimiser.java
@@ -638,7 +638,7 @@ public class GamsLocationOptimiser {
double supply = getParmValue(woodSupplyP, wType.getName());
WoodUsageData woodUsageData = inputData.getCountryInput().getPreviousWoodUsageData().get(wType);
woodUsageData.setProduction(supply);
- woodUsageData.setNetImport(netImports);
+ woodUsageData.updateNetImports(netImports);
newWoodUsageMap.put(wType, woodUsageData);
}
diff --git a/src/ac/ed/lurg/landuse/CarbonUsageData.java b/src/ac/ed/lurg/landuse/CarbonUsageData.java
index 00f052704664c385adaee0ec3a3806cdbde3932c..f5df4272bb1e6787960443228b316b906258296f 100644
--- a/src/ac/ed/lurg/landuse/CarbonUsageData.java
+++ b/src/ac/ed/lurg/landuse/CarbonUsageData.java
@@ -26,4 +26,8 @@ public class CarbonUsageData implements Serializable {
public double getNetCarbonFlux() {
return netCarbonFlux;
}
+
+ public void updateNetImports(double netImports) {
+ this.netCarbonImport = netImports;
+ }
}
diff --git a/src/ac/ed/lurg/landuse/WoodUsageData.java b/src/ac/ed/lurg/landuse/WoodUsageData.java
index 4d8034308583a4795eb234ed55c19ba83be56896..9d0d29ff06610b325ef8d4825eeca1e1706223f2 100644
--- a/src/ac/ed/lurg/landuse/WoodUsageData.java
+++ b/src/ac/ed/lurg/landuse/WoodUsageData.java
@@ -30,7 +30,7 @@ public class WoodUsageData implements Serializable {
return netImport;
}
- public void setNetImport(double netImport) {
+ public void updateNetImports(double netImport) {
this.netImport = netImport;
}