Implement delayed Central Bank policy application

src/main/java/housing/CentralBank.java

@@ -47,13 +47,13 @@ void init() {
  // Set initial monetary policy
  baseRate = config.CENTRAL_BANK_INITIAL_BASE_RATE;
  // Set initial LTV mandatory policy thresholds
- firstTimeBuyerHardMaxLTV = config.CENTRAL_BANK_LTV_HARD_MAX_FTB;
- homeMoverHardMaxLTV = config.CENTRAL_BANK_LTV_HARD_MAX_HM;
- buyToLetHardMaxLTV = config.CENTRAL_BANK_LTV_HARD_MAX_BTL;
+ firstTimeBuyerHardMaxLTV = 0.9999; // TODO: Set these as non-binding initial parameters in config file
+ homeMoverHardMaxLTV = 0.9999; // TODO: Set these as non-binding initial parameters in config file
+ buyToLetHardMaxLTV = 0.9999; // TODO: Set these as non-binding initial parameters in config file
  // Set initial LTI mandatory policy thresholds
- firstTimeBuyerSoftMaxLTI = config.CENTRAL_BANK_LTI_SOFT_MAX_FTB;
+ firstTimeBuyerSoftMaxLTI = 15.0; // TODO: Set these as non-binding initial parameters in config file
  firstTimeBuyerMaxFracOverSoftMaxLTI = config.CENTRAL_BANK_LTI_MAX_FRAC_OVER_SOFT_MAX_FTB;
- homeMoverSoftMaxLTI = config.CENTRAL_BANK_LTI_SOFT_MAX_HM;
+ homeMoverSoftMaxLTI = 15.0; // TODO: Set these as non-binding initial parameters in config file
  homeMoverMaxFracOverSoftMaxLTI = config.CENTRAL_BANK_LTI_MAX_FRAC_OVER_SOFT_MAX_HM;
  monthsToCheckLTI = config.CENTRAL_BANK_LTI_MONTHS_TO_CHECK;
  // Set initial affordability mandatory policy thresholds
@@ -66,8 +66,20 @@ void init() {
  * This method implements the policy strategy of the Central Bank
  *
  * @param coreIndicators The current value of the core indicators
+ * @param time The current model time
  */
- public void step(collectors.CoreIndicators coreIndicators) {
+ public void step(collectors.CoreIndicators coreIndicators, int time) {
+
+ if (time >= config.CENTRAL_BANK_POLICY_APPLICATION_TIME) {
+ // Update LTV mandatory policy thresholds
+ firstTimeBuyerHardMaxLTV = config.CENTRAL_BANK_LTV_HARD_MAX_FTB;
+ homeMoverHardMaxLTV = config.CENTRAL_BANK_LTV_HARD_MAX_HM;
+ buyToLetHardMaxLTV = config.CENTRAL_BANK_LTV_HARD_MAX_BTL;
+ // Update LTI mandatory policy thresholds
+ firstTimeBuyerSoftMaxLTI = config.CENTRAL_BANK_LTI_SOFT_MAX_FTB;
+ homeMoverSoftMaxLTI = config.CENTRAL_BANK_LTI_SOFT_MAX_HM;
+ }
+
  /* Use this method to express the policy strategy of the central bank by setting the value of the various limits
  in response to the current value of the core indicators.
 

src/main/java/housing/Config.java

@@ -49,6 +49,7 @@ public class Config {
 
  // Central Bank policy
  double CENTRAL_BANK_INITIAL_BASE_RATE; // Central Bank initial base rate
+ int CENTRAL_BANK_POLICY_APPLICATION_TIME; // Time step from which any (potentially binding) Central Bank policy is applied
  double CENTRAL_BANK_LTV_HARD_MAX_FTB; // Mandatory Central Bank policy: Hard maximum LTV ratio for first-time buyers
  double CENTRAL_BANK_LTV_HARD_MAX_HM; // Mandatory Central Bank policy: Hard maximum LTV ratio for home movers
  double CENTRAL_BANK_LTV_HARD_MAX_BTL; // Mandatory Central Bank policy: Hard maximum LTV ratio for BTL investors

src/main/java/housing/Model.java

@@ -205,7 +205,7 @@ private static void modelStep() {
  // Update bank and interest rate for new mortgages
  bank.step(Model.households.size());
  // Update central bank policies (currently empty!)
- centralBank.step(coreIndicators);
+ centralBank.step(coreIndicators, t);
  }
 
  /**

src/main/resources/config.properties

@@ -67,6 +67,8 @@ recordSavingRate = false
 # most of 2016 (since 16/03/2016 till present)
 # Note this parameter does not affect the dynamics of the model, only how the mortgage spread is reported
 CENTRAL_BANK_INITIAL_BASE_RATE = 0.0
+# Time step from which any (potentially binding) Central Bank policy is applied (int)
+CENTRAL_BANK_POLICY_APPLICATION_TIME = 500
 # Default value (0.000102459) is empirically input calibrated to the Main Refinancing Operations (MRO) rate set by the
 # ECB as an average over 2016 (0.0005 until 15/03/2016, that is, for 75 days, 0 from 16/03/2016, that is, for 291 days)
 #CENTRAL_BANK_INITIAL_BASE_RATE = 0.000102459