R/ESSOE.R

In SebastianBehrens/SolowVariants: Provide framework to simulate macroeconomic Solow growth models

### 3.0 Extended Solow Growth Model for the Small Open Economy #############################

SimulateExtendedSolowModelSmallOpenEconomy <- function(paragrid, np, startvals){

  # Roxygen Header ---------------------------------
  #' @title Simulates the ESSOE Solow variant
  #' @description Simulates all (both primary and secondary) endogenous variables to the extended Solow growth model for the small open economy.
  #' @inheritParams SimulateBasicSolowModel
  #' @note The structural equations to this model can be found in the vignette to this package:
  #' \code{vignette("SolowVariants")}
  #' @export

  # Function ---------------------------------
    
    # Load Basic Model Functions ---------------------------------
    # source("ModelFunctions/ESSOEModelFunctions.R")
    
    # Initialize Simulation Table ---------------------------------
    sim_table <- create_simulation_table(variable_encoder(getModelVars("ESSOE")), np)
    # Fill Start Values for Period 0 ---------------------------------
    aux_index <- which(sim_table$period == 0)
    sim_table[[aux_index, "L"]] <- startvals$L
    sim_table[[aux_index, "K"]] <- ESSOE_MF_K(paragrid[[aux_index, "r"]],
                                              paragrid[[aux_index, "alpha"]],
                                              paragrid[[aux_index, "B"]],
                                              sim_table[[aux_index, "L"]])
    
    sim_table[[aux_index, "V"]] <- startvals$V
    
    sim_table[[aux_index, "F"]] <- ESSOE_MF_F(sim_table[[aux_index, "V"]],
                                              sim_table[[aux_index, "K"]])
    
    sim_table[[aux_index, "Y"]] <- ESSOE_MF_Y(paragrid[[aux_index, "B"]], 
                                           sim_table[[aux_index, "K"]], 
                                           sim_table[[aux_index, "L"]], 
                                           paragrid[["alpha"]][[which(paragrid$period == 0)]])
    
    sim_table[[aux_index, "Yn"]] <- ESSOE_MF_Yn(sim_table[[aux_index, "Y"]], 
                                                paragrid[[aux_index, "r"]], 
                                                sim_table[[aux_index, "F"]])
    # Computing Variables after Period 0 ---------------------------------
    for (i in 1:np){
        # i <- 1
        aux_index <- which(sim_table$period == i)
        # VN for V next since in period 0 only the initial values are computed. every iteration 
        #                starts with computing the start values of V (the most important 'path defining' variable)
        sim_table[[aux_index, "V"]] <- ESSOE_MF_VN(sim_table[[aux_index - 1, "Yn"]], 
                                                   paragrid[[aux_index - 1, "s"]],
                                                   sim_table[[aux_index - 1, "V"]])
        
        sim_table[[aux_index, "L"]] <- ESSOE_MF_LN(paragrid[[aux_index - 1, "n"]],
                                                sim_table[[aux_index - 1, "L"]])
        
        sim_table[[aux_index, "K"]] <- ESSOE_MF_K(paragrid[[aux_index, "r"]],
                                                  paragrid[[aux_index, "alpha"]],
                                                  paragrid[[aux_index, "B"]],
                                                  sim_table[[aux_index, "L"]])
        
        sim_table[[aux_index, "F"]] <- ESSOE_MF_F(sim_table[[aux_index, "V"]],
                                                  sim_table[[aux_index, "K"]])
        
        sim_table[[aux_index, "Y"]] <- ESSOE_MF_Y(paragrid[[aux_index, "B"]], 
                                               sim_table[[aux_index, "K"]],
                                               sim_table[[aux_index, "L"]],
                                               paragrid[[aux_index, "alpha"]])
        
        sim_table[[aux_index, "Yn"]] <- ESSOE_MF_Yn(sim_table[[aux_index, "Y"]], 
                                                    paragrid[[aux_index, "r"]],
                                                    sim_table[[aux_index, "F"]])
        
    }
    
    # Computing Additional Variables ---------------------------------
    
    remaining_vars_to_compute_bool <- names(sim_table) %in% c("period", "L", "K", "Y", "V", "F", "Yn")
    
    sim_table <- add_var_computer(sim_table, remaining_vars_to_compute_bool, paragrid, "exo", "ESSOE")
    # View(sim_table)
    return(sim_table)
}