Add tourism: inbound/outbound services trade with seasonality, ER sensitivity, COVID shock (#47)

Author: speedcom

src/main/scala/sfc/Main.scala

@@ -191,7 +191,7 @@ def runSingle(seed: Int, rc: RunConfig): RunResult =
   //          Housing: HPI, MarketValue, MortgageStock, MortgageRate, Origination,
   //                   Repayment, Default, MortgageInterest, HhHousingWealth,
   //                   HousingWealthEffect, MortgageToGdp
-  val nCols = 190
+  val nCols = 194
   val results = Array.ofDim[Double](Config.Duration, nCols)
 
   for t <- 0 until Config.Duration do
@@ -494,7 +494,16 @@ def runSingle(seed: Int, rc: RunConfig): RunResult =
       },
       // Diaspora Remittances (#46)
       world.diasporaRemittanceInflow,                                                     // 188: DiasporaRemittanceInflow
-      world.diasporaRemittanceInflow - world.immigration.remittanceOutflow                 // 189: NetRemittances
+      world.diasporaRemittanceInflow - world.immigration.remittanceOutflow,                // 189: NetRemittances
+      // Tourism (#47)
+      world.tourismExport,                                                               // 190: TourismExport
+      world.tourismImport,                                                               // 191: TourismImport
+      world.tourismExport - world.tourismImport,                                         // 192: NetTourismBalance
+      {                                                                                  // 193: TourismSeasonalFactor
+        val monthInYear = (t % 12) + 1
+        1.0 + Config.TourismSeasonality *
+          Math.cos(2 * Math.PI * (monthInYear - Config.TourismPeakMonth) / 12.0)
+      }
     )
 
   RunResult(results, world.hhAgg)
@@ -527,7 +536,7 @@ def runSingle(seed: Int, rc: RunConfig): RunResult =
 
   // Aggregation arrays
   val nMonths = Config.Duration
-  val nCols   = 190
+  val nCols   = 194
   val allRuns = Array.ofDim[Double](nSeeds, nMonths, nCols)
   val allHhAgg = new Array[Option[HhAggregates]](nSeeds)
 
@@ -597,7 +606,8 @@ def runSingle(seed: Int, rc: RunConfig): RunResult =
     "AggInventoryStock;InventoryChange;InventoryToGdp;" +
     "EffectiveShadowShare;TaxEvasionLoss;InformalEmployment;EvasionToGdpRatio;" +
     "AggEnergyCost;EnergyCostToGdp;EtsPrice;AggGreenCapital;GreenInvestment;GreenCapitalRatio;" +
-    "DiasporaRemittanceInflow;NetRemittances\n")
+    "DiasporaRemittanceInflow;NetRemittances;" +
+    "TourismExport;TourismImport;NetTourismBalance;TourismSeasonalFactor\n")
   for seed <- 0 until nSeeds do
     val last = allRuns(seed)(nMonths - 1)
     termPw.write(s"${seed + 1}")
@@ -706,7 +716,8 @@ def runSingle(seed: Int, rc: RunConfig): RunResult =
     "AggInventoryStock", "InventoryChange", "InventoryToGdp",
     "EffectiveShadowShare", "TaxEvasionLoss", "InformalEmployment", "EvasionToGdpRatio",
     "AggEnergyCost", "EnergyCostToGdp", "EtsPrice", "AggGreenCapital", "GreenInvestment", "GreenCapitalRatio",
-    "DiasporaRemittanceInflow", "NetRemittances")
+    "DiasporaRemittanceInflow", "NetRemittances",
+    "TourismExport", "TourismImport", "NetTourismBalance", "TourismSeasonalFactor")
   // Header: Month, then for each metric: mean, std, p05, p95
   aggPw.write("Month")
   for c <- 1 until nCols do

src/main/scala/sfc/config/SimConfig.scala

@@ -895,6 +895,18 @@ object Config:
   val RemittanceGrowthRate: Double = sys.env.get("REMITTANCE_GROWTH_RATE").map(_.trim.toDouble).getOrElse(0.02)
   val RemittanceCyclicalSens: Double = sys.env.get("REMITTANCE_CYCLICAL_SENS").map(_.trim.toDouble).getOrElse(0.3)
 
+  // Tourism (#47)
+  val TourismEnabled: Boolean = sys.env.get("TOURISM_ENABLED").map(_.trim.toBoolean).getOrElse(false)
+  val TourismInboundShare: Double = sys.env.get("TOURISM_INBOUND_SHARE").map(_.trim.toDouble).getOrElse(0.05)
+  val TourismOutboundShare: Double = sys.env.get("TOURISM_OUTBOUND_SHARE").map(_.trim.toDouble).getOrElse(0.03)
+  val TourismErElasticity: Double = sys.env.get("TOURISM_ER_ELASTICITY").map(_.trim.toDouble).getOrElse(0.6)
+  val TourismSeasonality: Double = sys.env.get("TOURISM_SEASONALITY").map(_.trim.toDouble).getOrElse(0.40)
+  val TourismPeakMonth: Int = sys.env.get("TOURISM_PEAK_MONTH").map(_.trim.toInt).getOrElse(7)
+  val TourismGrowthRate: Double = sys.env.get("TOURISM_GROWTH_RATE").map(_.trim.toDouble).getOrElse(0.03)
+  val TourismShockMonth: Int = sys.env.get("TOURISM_SHOCK_MONTH").map(_.trim.toInt).getOrElse(0)
+  val TourismShockSize: Double = sys.env.get("TOURISM_SHOCK_SIZE").map(_.trim.toDouble).getOrElse(0.80)
+  val TourismShockRecovery: Double = sys.env.get("TOURISM_SHOCK_RECOVERY").map(_.trim.toDouble).getOrElse(0.03)
+
   // Heterogeneous households (Paper-06)
   val HhCount = sys.env.get("HH_COUNT").map(_.trim.toInt).getOrElse(TotalPopulation)
 

src/main/scala/sfc/engine/OpenEconomy.scala

@@ -3,6 +3,7 @@ package sfc.engine
 import sfc.config.{Config, SECTORS, RunConfig}
 import sfc.sfc.{ForexState, BopState}
 import sfc.agents.CentralBankLogic
+import sfc.engine.KahanSum.*
 
 case class OpenEconResult(
   forex: ForexState,
@@ -25,7 +26,9 @@ object OpenEconomy:
            gvcIntermImports: Option[Vector[Double]] = None,
            remittanceOutflow: Double = 0.0,
            euFundsMonthly: Double = 0.0,
-           diasporaInflow: Double = 0.0): OpenEconResult =
+           diasporaInflow: Double = 0.0,
+           tourismExport: Double = 0.0,
+           tourismImport: Double = 0.0): OpenEconResult =
 
     val nSectors = SECTORS.length
 
@@ -45,6 +48,7 @@ object OpenEconomy:
     val exports = gvcExports.getOrElse {
       Config.OeExportBase * foreignGdpFactor * realExRate * ulcEffect
     }
+    val totalExportsIncTourism = exports + tourismExport
 
     // B. Imported intermediates (cross-border I-O)
     // Intermediate imports = real domestic output × import share × ER net effect.
@@ -61,13 +65,13 @@ object OpenEconomy:
         realOutput * Config.OeImportContent(s) * erNetEffect
       }.toVector
     }
-    val totalImportedInterm = importedInterm.sum
+    val totalImportedInterm = importedInterm.kahanSum
 
     // C. Total imports
-    val totalImports = importCons + techImports + totalImportedInterm
+    val totalImports = importCons + techImports + totalImportedInterm + tourismImport
 
     // D. Trade balance
-    val tradeBalance = exports - totalImports
+    val tradeBalance = totalExportsIncTourism - totalImports
 
     // E. Current account
     val primaryIncome = prevBop.nfa * Config.OeNfaReturnRate / 12.0
@@ -112,7 +116,7 @@ object OpenEconomy:
     val newForeignAssets = prevBop.foreignAssets + Math.max(0.0, capitalAccount)
     val newForeignLiabilities = prevBop.foreignLiabilities + Math.max(0.0, -capitalAccount)
 
-    val newForex = ForexState(newExRate, totalImports, exports, tradeBalance, techImports)
+    val newForex = ForexState(newExRate, totalImports, totalExportsIncTourism, tradeBalance, techImports)
 
     val newBop = BopState(
       nfa = newNfa,
@@ -126,7 +130,7 @@ object OpenEconomy:
       fdi = fdi,
       portfolioFlows = portfolioFlows,
       reserves = prevBop.reserves + deltaReserves,
-      exports = exports,
+      exports = totalExportsIncTourism,
       totalImports = totalImports,
       importedIntermediates = totalImportedInterm
     )

src/main/scala/sfc/engine/Simulation.scala

@@ -500,6 +500,27 @@ object Simulation:
       base * erAdj * trendAdj * cyclicalAdj
     else 0.0
 
+    // Tourism services export/import (#47)
+    val (tourismExport, tourismImport) = if Config.TourismEnabled then
+      val monthInYear = (m % 12) + 1
+      val seasonalFactor = 1.0 + Config.TourismSeasonality *
+        Math.cos(2 * Math.PI * (monthInYear - Config.TourismPeakMonth) / 12.0)
+      val inboundErAdj = Math.pow(w.forex.exchangeRate / Config.BaseExRate, Config.TourismErElasticity)
+      val outboundErAdj = Math.pow(Config.BaseExRate / w.forex.exchangeRate, Config.TourismErElasticity)
+      val trendAdj = Math.pow(1.0 + Config.TourismGrowthRate / 12.0, m.toDouble)
+      val disruption = if Config.TourismShockMonth > 0 && m >= Config.TourismShockMonth then
+        Config.TourismShockSize * Math.pow(1.0 - Config.TourismShockRecovery,
+          (m - Config.TourismShockMonth).toDouble)
+      else 0.0
+      val shockFactor = 1.0 - disruption
+      val baseGdp = Math.max(0.0, w.gdpProxy)
+      val inbound = Math.max(0.0, baseGdp * Config.TourismInboundShare *
+        seasonalFactor * inboundErAdj * trendAdj * shockFactor)
+      val outbound = Math.max(0.0, baseGdp * Config.TourismOutboundShare *
+        seasonalFactor * outboundErAdj * trendAdj * shockFactor)
+      (inbound, outbound)
+    else (0.0, 0.0)
+
     // Consumer credit flows
     val aggConsumerDS = w.bank.consumerLoans * (Config.CcAmortRate + (lendingBaseRate + Config.CcSpread) / 12.0)
     val aggConsumerOrig = domesticCons * 0.02  // ~2% of consumption financed by credit
@@ -629,7 +650,9 @@ object Simulation:
         gvcIntermImports = gvcImp,
         remittanceOutflow = remittanceOutflow,
         euFundsMonthly = euMonthly,
-        diasporaInflow = diasporaInflow)
+        diasporaInflow = diasporaInflow,
+        tourismExport = tourismExport,
+        tourismImport = tourismImport)
       (oeResult.forex, oeResult.bop, oeResult.valuationEffect, oeResult.fxIntervention)
     else
       val fx = Sectors.updateForeign(w.forex, importCons, totalTechAndInvImports, autoR, w.nbp.referenceRate, gdp, rc)
@@ -818,6 +841,7 @@ object Simulation:
                    + corpBondBankCoupon * 0.3,
       deposits   = w.bank.deposits + (totalIncome - consumption) + jstDepositChange
                    + netDomesticDividends - foreignDividendOutflow - remittanceOutflow + diasporaInflow
+                   + tourismExport - tourismImport
                    + consumerOrigination + insNetDepositChange + nbfiDepositDrain,
       consumerLoans = Math.max(0.0, w.bank.consumerLoans + consumerOrigination - consumerPrincipal - consumerDefaultAmt),
       consumerNpl = Math.max(0.0, w.bank.consumerNpl + consumerDefaultAmt - w.bank.consumerNpl * 0.05),
@@ -909,9 +933,11 @@ object Simulation:
           val bankDivOutflow = foreignDividendOutflow * ws
           val bankRemittance = remittanceOutflow * ws
           val bankDiasporaInflow = diasporaInflow * ws
+          val bankTourismExport = tourismExport * ws
+          val bankTourismImport = tourismImport * ws
           val bankInsDepChange = insNetDepositChange * ws
           val bankNbfiDepDrain = nbfiDepositDrain * ws
-          val newDep = b.deposits + (bankIncomeShare - bankConsShare) + bankDivInflow - bankDivOutflow - bankRemittance + bankDiasporaInflow + bankCcOrig + bankInsDepChange + bankNbfiDepDrain
+          val newDep = b.deposits + (bankIncomeShare - bankConsShare) + bankDivInflow - bankDivOutflow - bankRemittance + bankDiasporaInflow + bankTourismExport - bankTourismImport + bankCcOrig + bankInsDepChange + bankNbfiDepDrain
           // Per-bank mortgage flows (proportional to deposit share)
           val bankDepShare = if totalWorkers > 0 then perBankWorkers(bId) / totalWorkers else 0.0
           val bankMortgageIntIncome = mortgageInterestIncome * bankDepShare
@@ -1077,7 +1103,9 @@ object Simulation:
       aggEnergyCost = sumEnergyCost,
       aggGreenCapital = aggGreenCapital,
       aggGreenInvestment = sumGreenInvestment,
-      diasporaRemittanceInflow = diasporaInflow)
+      diasporaRemittanceInflow = diasporaInflow,
+      tourismExport = tourismExport,
+      tourismImport = tourismImport)
 
     // SFC accounting check: verify exact balance-sheet identities every step
     val prevSnap = SfcCheck.snapshot(w, firms, households)
@@ -1137,7 +1165,9 @@ object Simulation:
       nbfiDefaultAmount = finalNbfi.lastNbfiDefaultAmount,
       fdiProfitShifting = sumProfitShifting,
       fdiRepatriation = sumFdiRepatriation,
-      diasporaInflow = diasporaInflow
+      diasporaInflow = diasporaInflow,
+      tourismExport = tourismExport,
+      tourismImport = tourismImport
     )
     val sfcResult = SfcCheck.validate(m, prevSnap, currSnap, sfcFlows)
     if !sfcResult.passed then

src/main/scala/sfc/engine/World.scala

@@ -53,5 +53,7 @@ case class World(
   aggEnergyCost: Double = 0.0,
   aggGreenCapital: Double = 0.0,
   aggGreenInvestment: Double = 0.0,
-  diasporaRemittanceInflow: Double = 0.0
+  diasporaRemittanceInflow: Double = 0.0,
+  tourismExport: Double = 0.0,
+  tourismImport: Double = 0.0
 )

src/main/scala/sfc/sfc/SfcCheck.scala

@@ -87,7 +87,9 @@ object SfcCheck:
     nbfiDefaultAmount: Double = 0.0,     // #42: NBFI gross monthly defaults
     fdiProfitShifting: Double = 0.0,     // #33: FDI profit shifting (service import)
     fdiRepatriation: Double = 0.0,       // #33: FDI dividend repatriation (primary income debit)
-    diasporaInflow: Double = 0.0         // #46: diaspora remittance inflow → deposit inflow
+    diasporaInflow: Double = 0.0,        // #46: diaspora remittance inflow → deposit inflow
+    tourismExport: Double = 0.0,         // #47: inbound tourism → deposit inflow + export
+    tourismImport: Double = 0.0          // #47: outbound tourism → deposit outflow + import
   )
 
   /** Result of the SFC check: ten exact balance-sheet identity checks. */
@@ -145,7 +147,7 @@ object SfcCheck:
     * The monetary circuit closes via sector-level flow-of-funds (Identity 10).
     *
     * 1. Bank capital:  Δ = -nplLoss - mortgageNplLoss - consumerNplLoss + (interestIncome + hhDebtService + bankBondIncome + mortgageInterestIncome + consumerDebtService - depositInterestPaid + reserveInterest + standingFacilityIncome + interbankInterest) × 0.3
-    * 2. Bank deposits: Δ = totalIncome - totalConsumption + jstDepositChange + dividendIncome - foreignDividendOutflow - remittanceOutflow + diasporaInflow + consumerOrigination + insNetDepositChange + nbfiDepositDrain
+    * 2. Bank deposits: Δ = totalIncome - totalConsumption + jstDepositChange + dividendIncome - foreignDividendOutflow - remittanceOutflow + diasporaInflow + tourismExport - tourismImport + consumerOrigination + insNetDepositChange + nbfiDepositDrain
     * 3. Gov debt:      Δ = govSpending - govRevenue  (govRevenue includes dividendTax + zusGovSubvention)
     * 4. NFA:           Δ = currentAccount + valuationEffect  (currentAccount includes -foreignDividendOutflow, -fdiProfitShifting, -fdiRepatriation, +diasporaInflow)
     * 5. Bond clearing: bankBondHoldings + nbpBondHoldings + ppkBondHoldings + insuranceGovBondHoldings + tfiGovBondHoldings = bondsOutstanding
@@ -178,9 +180,10 @@ object SfcCheck:
     val actualBankCapChange = curr.bankCapital - prev.bankCapital
     val bankCapErr = actualBankCapChange - expectedBankCapChange
 
-    // Identity 2: Bank deposits (+ JST deposit flows + dividend flows - remittance outflow + diaspora inflow + consumer origination + insurance + NBFI)
+    // Identity 2: Bank deposits (+ JST deposit flows + dividend flows - remittance outflow + diaspora inflow + tourism + consumer origination + insurance + NBFI)
     val expectedDepChange = flows.totalIncome - flows.totalConsumption + flows.jstDepositChange +
       flows.dividendIncome - flows.foreignDividendOutflow - flows.remittanceOutflow + flows.diasporaInflow +
+      flows.tourismExport - flows.tourismImport +
       flows.consumerOrigination + flows.insNetDepositChange + flows.nbfiDepositDrain
     val actualDepChange = curr.bankDeposits - prev.bankDeposits
     val bankDepErr = actualDepChange - expectedDepChange

src/test/scala/sfc/engine/IntegrationSpec.scala

@@ -18,7 +18,7 @@ class IntegrationSpec extends AnyFlatSpec with Matchers:
     val result = runSingle(42, rc)
     result.timeSeries.length shouldBe Config.Duration
     for row <- result.timeSeries do
-      row.length shouldBe 190
+      row.length shouldBe 194
   }
 
   it should "have Month column = 1..120" in {
@@ -44,7 +44,7 @@ class IntegrationSpec extends AnyFlatSpec with Matchers:
   it should "be reproducible with the same seed" in {
     val r1 = runSingle(42, rc)
     val r2 = runSingle(42, rc)
-    for t <- 0 until Config.Duration; c <- 0 until 190 do
+    for t <- 0 until Config.Duration; c <- 0 until 194 do
       r1.timeSeries(t)(c) shouldBe r2.timeSeries(t)(c)
   }