Why can't I get an if-statement maximum to return (correctly)?

I just need a smidge of help to determine the maximum value of the taxPayable assignment and it's associated name

Note: probably lots of things not perfect with my code XD

    import java.util.Scanner;
    import javax.swing.JOptionPane;

    public class Ass1dDialog
    {

    public static void main(String[] args)
        {
        double taxTotal = 0,  yearlyIncome = 0, maxTaxPayable = 0;
        int loopCounter = 0;
        final int loopMax = 3;
        String maxTaxPayerName = "";

        JOptionPane.showMessageDialog(null, "Welcome to the Tax Computation System");

        for(int x = 0; x < loopMax ; x++){

            String taxPayerName = "";
            taxPayerName = JOptionPane.showInputDialog("Enter the Tax Payer's Name");

            double taxPayable = computeTax(yearlyIncome);
            yearlyIncome = Double.parseDouble(JOptionPane.showInputDialog(" Enter income for " + taxPayerName + "")); //WRITE "Enter income for the tax payer==> "

            JOptionPane.showMessageDialog(null, "The tax that " + taxPayerName + " has to pay is $" + computeTax(yearlyIncome) + "\n");

this is the line(s) that I seem to be having the most trouble with

            if (computeTax(yearlyIncome) > maxTaxPayable){
                maxTaxPayable = taxPayable;

I have tried all sorts of positioning and methods of producing the maximum value. But for some reason it seems to display the wrong values, and I can't figure out why :[

            }

        }
        JOptionPane.showMessageDialog(null, "The maximum tax payable is $" + maxTaxPayable + ", payable by " + maxTaxPayerName + "\n");

}
    private static double computeTax(double yearlyIncome)
        {
        double          taxPayable, maxTaxPayable = 0;
        final double    RATE0 = 0,       ////
                        RATE1 = 18200,   //
                        RATE2 = 37000,   //
                        RATE3 = 87000,   //
                        RATE4 = 180000;  // - Tax rates for 2017
        final double    RATE_A = 0.19,   //
                        RATE_B = 0.325,  //
                        RATE_C = 0.37,   //
                        RATE_D = 0.47;   ////

            if (yearlyIncome < RATE1) {
                taxPayable = (yearlyIncome * RATE0);                     ////
            } else if (yearlyIncome < RATE2) {                           //
                taxPayable = ((yearlyIncome - RATE1) * RATE_A);          //
            } else if (yearlyIncome < RATE3) {                           //
                taxPayable = (3572 + (yearlyIncome - RATE2) * RATE_B);   // - Determine tax payable from yearly income input.
            } else if (yearlyIncome < RATE4) {                           //
                taxPayable = (19822 + (yearlyIncome - RATE3) * RATE_C);  //
            } else {                                                     //
                taxPayable = (54232 + (yearlyIncome - RATE4) * RATE_D);  ////
            }
            return taxPayable;
        }
}