def initialise_balance_sheet(self, iMethod):
"""Initialise the balance sheet, based on the bank lending and the parameters
Two approaches to determining the size of the balance sheet: through the assets and through the liabilities.
In both cases bank borrowing and lending are predetermined, and we have the desired capital ratio and cash ratio.
Then we either specify the external asset ratio or the financial liability ratio.
Finally, we do some adjustments to make sure that nothing is negative.
"""
capitalRatio = self.get_param('capitalRatio', required=True)
cashRatio = self.get_param('cashRatio', required=True)
loans = network.bank_lending(self.simInfo, self)
borrowings = network.bank_borrowing(self.simInfo, self)
if iMethod == "assets":
financialAssetRatio = self.get_param('financialAssetRatio', required=True)
externalAssets = loans * (1 - financialAssetRatio) / financialAssetRatio
totalAssets = loans + externalAssets
self.cash = cashRatio * totalAssets
initialInvestments = externalAssets - self.cash
initialCapital = capitalRatio * totalAssets
self.deposits = totalAssets - borrowings - initialCapital
if self.deposits < 0:
# can't have negative deposits. Make them zero, and increase cash by the same amount.
self.cash -= self.deposits
self.deposits = 0
# this will change all the ratios.
elif iMethod == "liabilities":
financialLiabilityRatio = self.get_param('financialLiabilityRatio', required=True)
self.deposits = borrowings / financialLiabilityRatio - borrowings
initialCapital = (self.deposits + borrowings) * capitalRatio / (1 - capitalRatio)
self.cash = cashRatio * (self.deposits + borrowings + initialCapital)
initialInvestments = initialCapital + borrowings + self.deposits - loans - self.cash
if initialInvestments < 0:
# can't have negative investments. Make them zero, and increase deposits by the same amount
self.deposits -= initialInvestments
initialInvestments = 0
else:
msg = "balanceSheetMethod %r not recognised" % iMethod
logger.error(msg)
raise ParameterError(msg)
self.initialise_investments(initialInvestments)
self.record_state()
def total_borrowing(self):
return network.bank_borrowing(self.simInfo, self)
