# Patent

## Title
Method, software program, and system for managing debt

## Abstract

In one embodiment, a method for managing variable rate debt in the form of at least one credit issued by a borrower, comprising: budgeting for interest owed on the variable rate debt by the borrower during a time period when an interest rate on the variable rate debt is below a first predetermined low interest rate level; applying at least a portion of any existing current budgetary excess by the borrower to reduce future interest rate risk by performing at least one of i) the early retirement of principal associated with the variable rate debt and ii) the funding of a sinking fund; and applying at least a portion of any accumulated budgetary excess by the borrower during a time period when the interest rate is above a first predetermined high interest rate level to reduce an amount of debt service. A corresponding software program and system are also disclosed.

## Background
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part of U.S. application Ser. No. 09/723,692, filed Nov. 28, 2000 now abandoned.


FIELD OF THE INVENTION
The present invention relates to a method, software program, and system for managing debt. More particularly, the present invention relates to a method, software program, and system for managing debt in the form of at least one credit issued by a borrower.
BACKGROUND OF THE INVENTION
Municipalities in general have debt structures that may rely exclusively or predominantly on fixed rate debt (such as “credits” in the form of loans, bonds, or other obligations). Some of the reasons may include the following:

    
    
        a) Fixed rated debt is accepted and municipal debt managers do not have to justify their decision to use it, even if it imposes an additional cost on the municipality (the additional cost may be in essence the cost of interest rate insurance against the possibility that increasing interest rates may cause the cost of variable rate debt in the future to exceed the cost that can be locked in with fixed rate debt).
        b) Interest rates may vary significantly within a budget period.
        c) A debt manager may face political risk by issuing variable rate debt. The political risk to the debt manager if he or she elects to issue variable rate debt is not just that the present value cost of variable rate debt may exceed the cost of fixed rated debt over the term of the debt, but also includes the possible risk of being criticized if rates spike in a particular year or group of years, even if the savings in prior years were significant and there were net savings overall (in some cases there may not even be legislative authority to issue variable rate debt, ostensibly due to the interest rate risk associated with such debt).
        d) Budgeting planned by a current debt manager may not be carried through in later years by subsequent debt managers and/or political decision makers (thus increasing future interest rate risk).
    
    


In issuing such traditional fixed rate debt (e.g., traditional municipal fixed rate bonds), a municipality pays its fixed rate bondholders a higher interest rate (versus non-fixed rate debt) to accept all of the risks and benefits of ownership of the municipal debt. In essence, the municipality purchases insurance against these risks from its fixed rate bondholders. The compensation to the fixed rate bondholders is both the higher fixed rate and the potential benefits associated with ownership of the debt.
On the other hand, when a municipality does utilize variable rate debt the changes over time in a municipality's variable interest rate generally occur because the issuer retains a variety of risks and benefits associated with ownership of municipal debt that, in the context of fixed rate debt, are transferred to the fixed rate bondholders. Thus, the issuer must generally revise the interest rate on its variable rate debt to reflect both favorable and unfavorable changes in market conditions that affect the value of ownership of the debt in order to keep the value of the debt essentially equal to par. The value of such traditional variable rate debt must be maintained essentially at par to motivate the current debt holder to retain its ownership or to enable the debt to be remarketed to a new holder if the debt is put back to the issuer by the current debt holder.
In any case, as seen in Table 1, a number of representative characteristics that generally affect the value of ownership of municipal debt (and the associated risks and benefits of ownership) include:







TABLE 1







Characteristics That Affect The Value of Ownership of


Municipal Bonds









Characteristic
Risk
Benefit





General level of interest rates
Increasing rates
Decreasing rates


Exemption from state/federal
Decrease in marginal
Tax increase


tax
tax rate or repeal



of exemption


Credit of issuer
Improvement in credit
Credit




deterioration


Credit of credit enhancer
Improvement in credit
Credit




deterioration


Credit of liquidity provider
Improvement in credit
Credit




deterioration


Supply and demand for
Increase in supply or
Decrease in


municipal bonds
decrease in demand
supply or increase




in demand









As noted above, by issuing traditional fixed rate debt, an issuer essentially fully hedges each of the above characteristics (i.e., the issuer fixes both the cost and the benefit derived from the issuance of the debt). In contrast, by issuing traditional variable rate debt, the issuer retains both the risk and benefit associated with each ownership value characteristic. Given a specific bond interest rate, adverse changes with respect to any ownership value characteristic would cause a decline in the value of the bond and positive changes would cause an increase in the value of the bond. Thus, the issuer must increase the bond interest rate to compensate for adverse changes in order to be able to remarket its bonds. On the other hand, positive changes allow the issuer to decrease its bond interest rate while still being able to remarket its bonds.
Finally, it is noted that fixed-payer interest rate swaps (in which the issuer makes a fixed rate payment and receives a variable rate payment that offsets the interest payable on the issuer's variable rate bonds) are used to create fixed rate debt “synthetically” by fully or partially hedging the risks of debt ownership. As seen in Table 2, the extent to which such risks are hedged is determined by the methodology used to calculate the variable rate swap payment received by the issuer:







TABLE 2







Alternatives For Hedging Interest Rate Risks With Fixed-Payer


Interest Rate Swaps









Variable swap payment
Risks hedged
Risks Not Hedged





Issuer's actual bond
Interest rates
None


interest rate
Federal and state taxes



Issuer credit



Credit enhancer



and liquidity



provider credit



Municipal supply and



demand


Bond Market Association
Interest rates
State taxes


(BMA) rate
Federal taxes
Issuer credit



Municipal supply and
Credit enhancer and



demand
liquidity provider




credit


BMA rate with a tax flip
Interest rates
State taxes


to a percentage of LIBOR
Partial hedge of
Issuer credit


upon certain events
federal tax risk
Credit enhancer


involving significant
Municipal supply and
and liquidity


changes in the value of
demand
provider credit


federal tax exemption

Federal tax risk not




fully hedged


Fixed percentage of LIBOR
Interest rate risk
Federal and state




taxes




Issuer credit




Credit enhancer and




liquidity provider




credit




Municipal supply




and demand









Of note is the fact that the risk of a deviation between the interest rate on an issuer's variable rate bonds and the variable payment received by the issuer on a fixed-payer swap is referred to as “basis risk”. Basis risk exists to some degree on any swap on which the payment received is not calculated using the issuer's actual interest rate.
Nevertheless, neither such traditional fixed rate debt, nor such traditional variable rate demand debt, nor such traditional fixed-payer interest rate swaps necessarily provides for the management of debt in a manner desired by the debt issuer.



BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A shows a flowchart of a method according to one embodiment of the present invention;
FIG. 1B shows a flowchart of a method according to another embodiment of the present invention;
FIG. 2A shows a block diagram of a software program according to another embodiment of the present invention;
FIG. 2B shows a block diagram of a software program according to another embodiment of the present invention;
FIG. 3 shows a block diagram of a system according to another embodiment of the present invention; and
FIGS. 4A-4T show various comparisons of fixed and variable rate options.



Among those benefits and improvements that have been disclosed, other objects and advantages of this invention will become apparent from the following description taken in conjunction with the accompanying figures. The figures constitute a part of this specification and include exemplary embodiments of the present invention and illustrate various objects and features thereof.
DETAILED DESCRIPTION OF THE INVENTION
As required, detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention that may be embodied in various forms. The figures are not necessarily to scale, some features may be exaggerated to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present invention.
In one embodiment, a method for managing variable rate debt comprising: budgeting for interest owed on the variable rate debt by the borrower during a time period when an interest rate on the variable rate debt is below a first predetermined low interest rate level; applying at least a portion of any existing current budgetary excess by the borrower to reduce future interest rate risk by performing at least one of i) the early retirement of principal associated with the variable rate debt and ii) the funding of a sinking fund; and applying at least a portion of any accumulated budgetary excess by the borrower during a time period when the interest rate is above a first predetermined high interest rate level to reduce an amount of debt service.
In another embodiment, the method may further comprise the step of extending a principal amortization period associated with the variable rate debt by the borrower to maintain the amount of debt service below a predetermined debt service level during the time period when the interest rate is above a second predetermined high interest rate level and the impact of the performance of at least one of i) the early retirement of principal and ii) the application to principle and interest of amounts available in the sinking fund is not sufficient to avoid an increase in the amount of debt service above the predetermined debt service level, wherein the first predetermined high interest rate level and second predetermined high interest rate level are selected from the group of i) different levels and ii) the same levels.
In yet another embodiment, the method may further comprise the step of reducing a principal amortization period associated with the variable rate debt by the borrower during the time period when the interest rate is below a second predetermined low interest rate level, wherein the first predetermined low interest rate level and second predetermined low interest rate level are selected from the group of i) different levels and ii) the same levels.
In a further embodiment, a software program for managing variable rate debt comprises: budgeting means for calculating a budget for interest owed on the variable rate debt during a time period when an interest rate on the variable rate debt is below a first predetermined low interest rate level; current budgetary excess disposition calculation means for calculating a value of at least a portion of any existing current budgetary excess to be applied to reduce future interest rate risk by performing at least one of i) the early retirement of principal associated with the variable rate debt and ii) the funding of a sinking fund; and accumulated budgetary excess disposition calculation means for calculating a value of at least a portion of any accumulated budgetary excess to be applied during a time period when the interest rate is above a first predetermined high interest rate level to reduce an amount of debt service.
In another embodiment, the software program may further comprise a principal amortization extension calculation means for calculating an extension to a principal amortization period associated with the variable rate debt to maintain the amount of debt service below a predetermined debt service level during the time period when the interest rate is above a second predetermined high interest rate level and the impact of the performance of at least one of i) the early retirement of principal and ii) the application to principle and interest of amounts available in the sinking fund is not sufficient to avoid an increase in the amount of debt service above the predetermined debt service level, wherein the first predetermined high interest rate level and second predetermined high interest rate level are selected from the group of i) different levels and ii) the same levels.
In yet another embodiment, a system for managing variable rate debt comprises: memory means for storing a software program; and processing means for processing the software program; wherein the software program includes: budgeting means for calculating a budget for interest owed on the variable rate debt during a time period when an interest rate on the variable rate debt is below a first predetermined low interest rate level; current budgetary excess disposition calculation means for calculating a value of at least a portion of any existing current budgetary excess to be applied to reduce future interest rate risk by performing at least one of i) the early retirement of principal associated with the variable rate debt and ii) the funding of a sinking fund; and accumulated budgetary excess disposition calculation means for calculating a value of at least a portion of any accumulated budgetary excess to be applied during a time period when the interest rate is above a first predetermined high interest rate level to reduce an amount of debt service.
In yet a further embodiment, the system may further include the software program further comprising principal amortization extension calculation means for calculating an extension to a principal amortization period associated with the variable rate debt to maintain the amount of debt service below a predetermined debt service level during the time period when the interest rate is above a second predetermined high interest rate level and the impact of the performance of at least one of i) the early retirement of principal and ii) the application to principle and interest of amounts available in the sinking fund is not sufficient to avoid an increase in the amount of debt service above the predetermined debt service level, wherein the first predetermined high interest rate level and second predetermined high interest rate level are selected from the group of i) different levels and ii) the same levels.
In an embodiment, a method for managing debt created by an issuer using an interest rate swap in which the issuer makes a fixed rate payment and receives a variable rate payment that at least partially offsets an interest payment on a variable rate bond issued by the issuer, comprises: budgeting an amount by the issuer to cover the fixed rate payment, wherein the budgeted amount is higher than the amount of the fixed rate payment; and applying at least a portion of any current budgetary excess by the issuer resulting from the receipt of the variable rate payment at a level that produces a payment higher than the interest payment on the variable rate bond to perform at least one of i) the early retirement of principal associated with the synthetic fixed rate debt and ii) the funding of a sinking fund.
In a further embodiment, the method further comprises the step of applying at least a portion of any funds in the sinking fund by the issuer to the interest payment on the variable rate bond if the interest payment on the variable rate bond increases above a predetermined high interest rate level.
In yet another embodiment, the method further comprises the step of extending a principal amortization period by the issuer associated with the variable rate bond when the variable rate payment received by the issuer is less than the interest payment on the variable rate bond.
In another embodiment, a method for managing variable rate debt comprises: obligating the borrower to budget for interest owed on the variable rate debt during a time period when an interest rate on the variable rate debt is below a first predetermined low interest rate level to produce a current budgetary excess; and obligating at least a portion of the current budgetary excess be applied by the borrower to reduce future interest rate risk by performing at least one of i) the early retirement of principal associated with the variable rate debt and ii) the funding of a sinking fund.
In yet another embodiment, the method further comprises obligating that at least a portion of any accumulated budgetary excess be applied by the borrower during a time period when the interest rate is above a first predetermined high interest rate level to reduce an amount of debt service associated with the variable rate debt.
In yet another embodiment, the method of further comprises obligating that at least a portion of any accumulated funds in the sinking fund be applied by the borrower during a time period when the interest rate is above a first predetermined high interest rate level to reduce an amount of debt service associated with the variable rate debt.
In a further embodiment, the borrower may be allowed or required to apply at least one of the current budgetary excess and the accumulated budgetary excess to different credits within a fund of credits. At least two of the credits in the fund of credits may be issued at different times.
The software program may further comprise principal amortization reduction calculation means for calculating a reduction to a principal amortization period associated with the variable rate debt during the time period when the interest rate is below a second predetermined low interest rate level, wherein the first predetermined low interest rate level and second predetermined low interest rate level are selected from the group of i) different levels and ii) the same levels.
In one embodiment, the credit may be a bond.
The software program of the system may further comprise principal amortization reduction calculation means for calculating a reduction to a principal amortization period associated with the variable rate debt during the time period when the interest rate is below a second predetermined low interest rate level, wherein the first predetermined low interest rate level and second predetermined low interest rate level are selected from the group of i) different levels and ii) the same levels.
In another embodiment a method for managing basis risk associated with synthetic fixed rate debt created by an issuer using an interest rate swap in which the issuer makes a fixed rate payment and receives a variable rate payment that at least partially offsets an interest payment on a variable rate bond issued by the issuer is provided, including: allowing or requiring the issuer to budget a budgeted amount to cover the fixed rate payment, wherein the budgeted amount is higher than the amount of the fixed rate payment; and allowing or requiring the issuer to use at least a portion of any current budgetary excess resulting from the receipt of the variable rate payment at a level that produces a payment higher than the interest payment on the variable rate bond to perform at least one of i) the early retirement of principal associated with the synthetic fixed rate debt and ii) the funding of a sinking fund.
The method may further comprise allowing or requiring the issuer to apply at least a portion of any funds in the sinking fund to the interest payment on the variable rate bond if the interest payment on the variable rate bond increases above a predetermined high interest rate level.
The predetermined high interest rate level may be a predetermined excess over a current interest rate associated with the variable rate payment to the issuer.
Any amounts applied from the sinking fund may be excluded from a rate covenant calculation associated with the synthetic fixed rate debt.
The method may further comprise the step of allowing or requiring the issuer to extend a principal amortization period associated with the variable rate bond when the variable rate payment received by the issuer is less than the interest payment on the variable rate bond.
The method may further comprise the step of allowing or requiring the issuer to reduce a principal amortization period associated with the variable rate bond when the variable rate payment received by the issuer exceeds the interest payment on the variable rate bond.
In another embodiment a software program for managing basis risk associated with synthetic fixed rate debt created by an issuer using an interest rate swap in which the issuer makes a fixed rate payment and receives a variable rate payment that at least partially offsets an interest payment on a variable rate bond issued by the issuer is provided, including: budgeting means for calculating a budgeted amount to cover the fixed rate payment, wherein the budgeted amount is higher than the amount of the fixed rate payment; and current budgetary excess disposition calculation means for calculating the value of at least a portion of any current budgetary excess resulting from the receipt of the variable rate payment at a level that produces a payment higher than the interest payment on the variable rate bond to perform at least one of i) the early retirement of principal associated with the synthetic fixed rate debt and ii) the funding of a sinking fund.
The software program may further comprise sinking fund disposition calculation means for calculating the value of at least a portion of any funds in the sinking fund to be applied to the interest payment on the variable rate bond if the interest payment on the variable rate bond increases above a predetermined high interest rate level.
The predetermined high interest rate level may be a predetermined excess over a current interest rate associated with the variable rate payment to the issuer.
The software program may further comprise principal amortization extension calculation means for calculating an extension to a principal amortization period associated with the variable rate bond when the variable rate payment received by the issuer is less than the interest payment on the variable rate bond.
The software program may further comprise principal amortization reduction calculation means for calculating a reduction in a principal amortization period associated with the variable rate bond when the variable rate payment received by the issuer exceeds the interest payment on the variable rate bond.
In another embodiment a system for managing basis risk associated with synthetic fixed rate debt created by an issuer using an interest rate swap in which the issuer makes a fixed rate payment and receives a variable rate payment that at least partially offsets an interest payment on a variable rate bond issued by the issuer is provided, including: memory means for storing a software program; and processing means for processing the software program; wherein the software program includes: budgeting means for calculating a budgeted amount to cover the fixed rate payment, wherein the budgeted amount is higher than the amount of the fixed rate payment; and current budgetary excess disposition calculation means for calculating the value of at least a portion of any current budgetary excess resulting from the receipt of the variable rate payment at a level that produces a payment higher than the interest payment on the variable rate bond to perform at least one of i) the early retirement of principal associated with the synthetic fixed rate debt and ii) the funding of a sinking fund.
The software program of the system may further comprise sinking fund disposition calculation means for calculating the value of at least a portion of any funds in the sinking fund to be applied to the interest payment on the variable rate bond if the interest payment on the variable rate bond increases above a predetermined high interest rate level.
The predetermined high interest rate level may be a predetermined excess over a current interest rate associated with the variable rate payment to the issuer.
The software program of the system may further comprise principal amortization extension calculation means for calculating an extension to a principal amortization period associated with the variable rate bond when the variable rate payment received by the issuer is less than the interest payment on the variable rate bond.
The software program of the system may further comprise principal amortization reduction calculation means for calculating a reduction in a principal amortization period associated with the variable rate bond when the variable rate payment received by the issuer exceeds the interest payment on the variable rate bond.
More particularly, the present invention provides for what will hereinafter be referred to as the Municipal Interest Rate Risk Management Program (“MIRRMP”). In one embodiment of the present invention the MIRRMP may be applied to variable rate debt (e.g., unhedged variable rate debt). Under this embodiment of the MIRRMP approach, the use of variable rate debt by municipal debt managers (or by municipalities that have not yet authorized variable rate debt due to concerns about interest rate risk) is facilitated by helping to reduce the political risk to the debt managers and municipalities if interest rates rise. The MIRRMP approach as applied to variable rate debt may include one or more of the following: a) allowing or requiring conservative budgeting for variable rate debt interest while interest rates are low (e.g., wherein conservative budgeting may include budgeting at a fixed rate and/or at a higher interest rate than is actually expected); b) allowing or requiring that an amount of the current budgetary excess determined by formula be applied to reduce future interest rate risk either by retiring principal early or by funding a sinking fund; c) allowing or requiring the accumulated budgetary excess to be applied in future years when rates are high to reduce the amount of annual debt service; d) allowing or requiring current and accumulated budgetary excess to be applied (whether by retiring debt or by funding a sinking fund for a higher yield bond or a taxable bond, for example) across a series of credits (such as variable rate bonds and/or or fixed rate bonds) issued at different times in order to apply the excess in the most financially advantageous way and to reduce the impact of federal arbitrage limitations.
Further, for borrowers (or “issuers”) with a variety of credits within a particular fund, the MIRRMP approach may allow or require the budgetary excess to be applied across different credits.
Further still, to reduce the probability of a spike in rates causing a budgetary problem even in early years, the MIRRMP approach may allow or require the extension of the principal amortization (e.g., from 30 to 35 years) to maintain annual debt service at a predetermined level if rates should rise and the impact of a) the early retirement of principal and/or b) amounts available in the sinking fund to be applied to principal and interest is not sufficient to avoid an increase in debt service.
Further still, when rates are low a higher amortization (i.e., a reduction in term) could be allowed or required compared to the amortization associated with fixed rate credits. Conversely, when rates are high a reduced (i.e., an extended term) or eliminated amortization could be allowed or required in order to maintain debt service at a predetermined budgetary level.
Further still, it is believed that the MIRRMP approach should allow an issuer to exceed the standard 20% limit on variable rate debt (excluding those hedged by short-term assets) imposed by some rating agencies (e.g., STANDARD & POORS) since the interest risk is significantly reduced. In fact, it is believed that the MIRRMP approach could even obtain the issuer a rating benefit because the practical impact of the MIRRMP is likely to amortize debt more quickly.
Further still, for an issuer that comes to market regularly, the interest risk could be additionally reduced by issuing a portion of each financing as variable rate debt. So, even if rates rise generally, the savings from later issues together with the accumulated excess from earlier issues could be sufficient to prevent debt service from exceeding a predetermined budgetary amount. For an issuer with a lot of outstanding debt, the same economic effect could be accomplished by periodically converting a portion of the issuer's debt to variable rate debt through the use of interest rate swaps.
Typically, income from a municipality's short-term assets is generally affected by changes in interest rates in a manner inverse to the cost of variable rate debt. In other words, during times of rising interest rates, the additional income from a municipality's short term assets would likely offset any increase in the cost of the municipality's variable rate debt. Conversely, during times of falling interest rates, the reduced income from a municipality's short term assets would likely be offset by a decrease in the cost of the municipality's variable rate debt. Thus, combining variable rate debt (rather than fixed rate debt) with a municipality's variable rate assets should result in budgetary stability in that net debt service (variable rate debt service less earnings of short term assets) remains relatively constant regardless of what happens to interest rates. By contrast, combining fixed rated debt with variable rate assets should result in higher net debt service if rates either remain near current levels or go down and lower net debt service if rates increase significantly (producing budgetary volatility as rates rise or fall).
In addition, if financial conditions produce: a) an inverted tax-exempt yield curve (which, it is believed, is generally not seen); and/or b) a significant decrease in the federal tax rate then a borrower could incur current year losses on earlier variable interest rate debt (versus the fixed rates at which the credits, such as bonds, could have been issued).
In another embodiment of the present invention, the MIRRMP may be applied to moderate basis risk associated with an interest rate swap.
More particularly, just as the MIRRMP approach of the present invention can be used to manage the budgetary impact of unhedged variable rate debt, it can also be employed to manage the budgetary impact of basis risk for synthetic fixed rated debt.
In one particular example (which is intended for illustration only, and is not intended to be restrictive), assume that an issuer creates synthetic fixed rate debt using a fixed-payer swap under which the variable rate received by the issuer equals BMA (“Bond Market Association”), with a tax flip to 65% of the London Interbank Offered Rate (“LIBOR”) if the marginal tax rate is reduced below 25%. The issuer would have four potential sources of basis risk:

    
    
        1. Issuer credit risk;
        2. Credit enhancer and liquidity provider credit risk
        3. State tax risk; and
        4. Federal tax risk if a tax flip occurs.
    
    


Further, assume that the issuer's variable rate debt is expected to trade at BMA and that the issuer's fixed swap payment is equal to 4.50%.
Given these conditions, the issuer could obligate itself under the MIRRMP approach of the present invention to budget at a slightly higher amount based on a 4.52% fixed swap rate and to receive a variable payment based on BMA plus 2 basis points. To the extent that the issuer's variable rate debt trades, as expected, at BMA or better, the excess amounts received by the issuer could be used to retire principal and/or to fund a sinking fund. Amounts in the sinking fund could be drawn upon in later years if the variable rate debt traded at a rate higher than BMA plus 2 basis points in order to mitigate the budgetary impact of the basis mismatch. Amounts funded from the sinking fund could be excluded from the rate covenant calculation.
Moreover, the variable rate debt could be structured under the MIRRMP approach of the present invention with a longer nominal maturity and with an amortization determined by formula. To the extent that the issuer's variable rate exceeds the variable swap payments (including the results of a tax flip), the amortization could be adjusted (e.g., extended) so as to maintain the issuer's budgetary requirement unchanged. Similarly, additional principal could be amortized from any amounts by which the variable swap payment exceeds the issuer's variable rate. It is noted that the ability to adjust the amortization may be limited by legal requirements governing amortization of the issuer's bonds.
Referring now to FIG. 1A, a flowchart showing a method for managing variable rate debt according to one embodiment of the present invention is shown. As seen in this Fig., starting at Step 101a a borrower begins an action cycle. Each action cycle may occur periodically, such as monthly or annually, for example. During an action cycle the borrower (or the borrower's representative) carries out each step of the method as required given prevailing interest rates and budgetary excess.
More particularly, it is seen that at Step 103a the borrower is required to conservatively budget for interest owed on the variable rate debt during a time period when an interest rate on the variable rate debt is below a first predetermined low interest rate level. At Step 105a the borrower is required to apply at least a portion of any existing current budgetary excess to reduce future interest rate risk by performing at least one of i) the early retirement of principal associated with the variable rate debt and ii) the funding of a sinking fund. At Step 107a the borrower is required to apply at least a portion of any accumulated budgetary excess during a time period when the interest rate is above a first predetermined high interest rate level to reduce an amount of debt service associated with the variable rate debt. At Step 109a the borrower is required to extend a principal amortization period associated with the variable rate debt to maintain the amount of debt service below a predetermined debt service level during the time period when the interest rate is above a second predetermined high interest rate level and the impact of the performance of at least one of i) the early retirement of principal and ii) the application to principle and interest of amounts available in the sinking fund is not sufficient to avoid an increase in the amount of debt service above the predetermined debt service level, wherein the first predetermined high interest rate level and second predetermined high interest rate level are selected from the group of i) different levels and ii) the same levels. At Step 111a the borrower is required to reduce a principal amortization period associated with the variable rate debt during the time period when the interest rate is below a second predetermined low interest rate level, wherein the first predetermined low interest rate level and second predetermined low interest rate level are selected from the group of i) different levels and ii) the same levels. The borrower may be required to apply at least one of the current budgetary excess and the accumulated budgetary excess to different credits within a fund of credits. At least two of the credits in the fund of credits may be issued at different times and one or more of the credits may be a bond.
It should be noted that the steps described above do not necessarily need to be carried out in the order indicated and not all steps necessarily need to be carried out during any given cycle.
Referring now to FIG. 1B, a flowchart showing a method for managing basis risk associated with synthetic fixed rate debt created by an issuer using an interest rate swap in which the issuer makes a fixed rate payment and receives a variable rate payment that at least partially offsets an interest payment on a variable rate bond issued by the issuer according to another embodiment of the present invention is shown. As seen in this Fig., starting at Step 101b an issuer begins an action cycle. Each action cycle may occur periodically, such as monthly or annually, for example. During an action cycle the issuer (or the issuer's representative) carries out each step of the method as required given prevailing interest rates and budgetary excess.
More particularly, it is seen that at Step 103b the issuer is required to budget a budgeted amount to cover the fixed rate payment, wherein the budgeted amount is higher than the amount of the fixed rate payment. At Step 105b the issuer is required to apply at least a portion of any current budgetary excess resulting from the receipt of the variable rate payment at a level that produces a payment higher than the interest payment on the variable rate bond to perform at least one of i) the early retirement of principal associated with the synthetic fixed rate debt and ii) the funding of a sinking fund. At Step 107b the issuer is required to apply at least a portion of any funds in the sinking fund to the interest payment on the variable rate bond if the interest payment on the variable rate bond increases above a predetermined high interest rate level. The predetermined high interest rate level may be a predetermined excess over a current interest rate associated with the variable rate payment to the issuer. Any amounts applied from the sinking fund may be excluded from a rate covenant calculation associated with the synthetic fixed rate debt. At Step 109b an amortization period of the variable rate bond is extended when the variable rate payment received by the issuer is less than the interest payment on the variable rate bond. At Step 111b an amortization period of the variable rate bond is reduced when the variable rate payment received by the issuer exceeds the interest payment on the variable rate bond.
It should be noted that the steps described above do not necessarily need to be carried out in the order indicated and not all steps necessarily need to be carried out during any given cycle. For example, in one embodiment, after Step 101b, Steps 103b, 105b and 107b are conducted together. In another embodiment, after Step 101b, only Step 109b is conducted. In yet another embodiment, after Step 101b, Steps 103b, 105b, 107b and 109b are conducted together. In a further embodiment, after Step 101b, Steps 109b and 111b are conducted together. In yet a further embodiment, after Step 101b, only Step 111b is conducted.
Referring now to FIG. 2A, a block diagram of a software program for managing variable rate debt according to one embodiment of the present invention is shown. As seen in this Fig., Software Program 201a includes:

    
    
        1) Budgeting Module 203a for calculating a conservative budget for interest owed on the variable rate debt during a time period when an interest rate on the variable rate debt is below a first predetermined low interest rate level;
        2) Current Budgetary Excess Disposition Calculation Module 205a for calculating a value of at least a portion of any existing current budgetary excess to be applied to reduce future interest rate risk by performing at least one of i) the early retirement of principal associated with the variable rate debt and ii) the funding of a sinking fund;
        3) Accumulated Budgetary Excess Disposition Calculation Module 207a for calculating a value of at least a portion of any accumulated budgetary excess to be applied during a time period when the interest rate is above a first predetermined high interest rate level to reduce an amount of debt service associated with the variable rate debt;
        4) Principal Amortization Extension Calculation Module 209a for calculating an extension to a principal amortization period associated with the variable rate debt to maintain the amount of debt service below a predetermined debt service level during the time period when the interest rate is above a second predetermined high interest rate level and the impact of the performance of at least one of i) the early retirement of principal and ii) the application to principle and interest of amounts available in the sinking fund is not sufficient to avoid an increase in the amount of debt service above the predetermined debt service level, wherein the first predetermined high interest rate level and second predetermined high interest rate level are selected from the group of i) different levels and ii) the same levels; and
        5) Principal Amortization Reduction Calculation Module 211a for calculating a reduction to a principal amortization period associated with the variable rate debt during the time period when the interest rate is below a second predetermined low interest rate level, wherein the first predetermined low interest rate level and second predetermined low interest rate level are selected from the group of i) different levels and ii) the same levels.
    
    


Referring now to FIG. 2B, a block diagram of a software program for managing basis risk associated with synthetic fixed rate debt created by an issuer using an interest rate swap in which the issuer makes a fixed rate payment and receives a variable rate payment that at least partially offsets an interest payment on a variable rate bond issued by the issuer according to one embodiment of the present invention is shown. As seen in this Fig., Software Program 201b includes:

    
    
        1) Budgeting Module 203b for calculating a budgeted amount to cover the fixed rate payment, wherein the budgeted amount is higher than the amount of the fixed rate payment;
        2) Current Budgetary Excess Disposition Calculation Module 205b for calculating the value of at least a portion of any current budgetary excess resulting from the receipt of the variable rate payment at a level that produces a payment higher than the interest payment on the variable rate bond to perform at least one of i) the early retirement of principal associated with the synthetic fixed rate debt and ii) the funding of a sinking fund;
        3) Sinking Fund Disposition Calculation Module 207b for calculating the value of at least a portion of any funds in the sinking fund to be applied to the interest payment on the variable rate bond if the interest payment on the variable rate bond increases above a predetermined high interest rate level;
        4) Principal Amortization Extension Calculation Module 209b for calculating an extension to a principal amortization period associated with the variable rate bond when the variable rate payment received by the issuer is less than the interest payment on the variable rate bond; and
        5) Principal Amortization Reduction Calculation Module 211b for calculating a reduction in a principal amortization period associated with the variable rate bond when the variable rate payment received by the issuer exceeds the interest payment on the variable rate bond.
    
    


Referring now to FIG. 3, a block diagram of a system according to one embodiment of the present invention is shown. As seen in this Fig., Computer 301 includes Memory 303 for storing a software program (not shown) and CPU 305 for processing the software program. Monitor 307, Keyboard 309, Mouse 311, and Printer 313 are connected to Computer 301 to provide user input/output. Input/output to the software program may also be accomplished via a storage medium (e.g., a hard drive or a CD) and/or a network, each of which is not shown The software program stored in Memory 303 and processed by CPU 305 may of course be one of the software programs of the present invention. In any case, the details of each of Computer 301, Memory 303, CPU 305, Monitor 307, Keyboard 309, Mouse 311, and Printer 313 are well known to those of ordinary skill in the art and will not be discussed further.
In another embodiment of the present invention, the MIRRMP may be applied to aid an issuer in maximizing current savings from the use of variable rate debt while essentially achieving budgetary certainty for a current year. It is noted that this embodiment of the present invention does not necessarily eliminate budgetary volatility from year to year but, rather, essentially gives the issuer certainty that the budgeted amount for a current year will be the actual debt service due.
More particularly, as an alternative to requiring that an issuer budget conservatively (for example, at a higher interest rate than is actually expected) in order to insure that budgeted funds are sufficient, application of the MIRRMP approach according to this embodiment of the present invention makes use of the flexibility to modify the amortization of variable rate debt to essentially provide budgetary certainty for a current year.
One particular example of this embodiment of the present invention (which is intended for illustration only, and is not intended to be restrictive), may operate as follows:

    
    
        (A) The issuer would be required to budget for the expected amount of interest on its variable rate bonds (“VRDBs”). The determination of the expected amount of interest could be left either partially or entirely to the issuer and/or the expected amount of interest could be required to equal at least some minimum, such as the prior year's interest, for example.
        (B) In addition, the issuer would be required to increase or decrease the amount budgeted under (A) for the current year by the amount by which the prior year's actual interest exceeded or was less than the amount budgeted under (A) for the prior year.
        (C) The planned principal amortization for the current year would be: i) increased or decreased by the amount by which the actual interest for the current year is less than or greater than the amount budgeted under (A) for the current year; and ii) increased or decreased by the amount increased or decreased under (B) for the current year.
    
    


Thus, the amount budgeted for principal and interest would equal the actual principal and interest payable in the current year. However, the allocation between principal and interest could be different than the amount initially reflected in the budget by the difference between the actual interest rate and the rate budgeted under (A).
While a number of embodiments of the present invention have been described, it is understood that these embodiments are illustrative only, and not restrictive, and that many modifications may become apparent to those of ordinary skill in the art. For example, the credit or credits may include one or more bonds. Further, at least one of a) a portion of the current budgetary excess and b) a portion of the accumulated budgetary excess may be applied by the borrower across different credits within a fund of credits. Further still, at least one of a) a portion of the current budgetary excess and b) a portion of the accumulated budgetary excess may applied by the borrower across a series of credits issued at different times. Further still, at least one of a) a portion of the current budgetary excess and b) a portion of the accumulated budgetary excess may be applied by the borrower across a series of credits including both a variable rate credit and a fixed rate credit. Further still, in the event that during any year, budgeted funds for interest and funds set aside for interest mitigation are not sufficient to cover debt service, a Debt Service Reserve Fund (“DSRF”) might be made available to find the excess. Monies could then be budgeted to find the DSRF deficiency in the succeeding year(s). Also, in the event that the interest rate were to exceed the amortization rate, an alternative approach could be to make the reserve available to delay the point at which the issuer would have to budget in excess of the amortization rate. (This feature may create credit concerns with some rating agencies). Further still, other reserves not typically available to pay debt service (e.g., a renewal and replacement fund intended to be used only for extraordinary repairs) could be similarly used. Further still, the methods described may be carried out via requirements included in one or more legal or financial instruments. Further still, the present invention may be utilized to manage risk (e.g., interest rate risk) in the context of unhedged, and/or imperfectly hedged variable rate and/or fixed rate debt (either “natural” or synthetic”). Further still, the first predetermined low interest rate level and/or the second predetermined low interest rate level may be equal to or different from the first predetermined high interest rate level and/or the second predetermined high interest rate level. Further still, various interest rates indicated as being below predetermined interest rate levels may, of course, be below or equal to the predetermined interest rate levels. Likewise, various interest rates indicated as being above predetermined interest rate levels may, of course, be above or equal to the predetermined interest rate levels. Further still, the term “current” (used with the phrase “current budgetary excess”, for example) may apply to any appropriate current period, such as this year, this month, or this week, for example. Further still, the term “accumulated” (used with the phrase “accumulated budgetary excess”, for example) may apply to any accumulation from an appropriate prior period, such as last year, last month, or last week, for example. Further still, the memory of the system may comprise a magnetic hard drive, a magnetic floppy disk, a compact disk, a ROM, a RAM, and/or any other appropriate memory. Further still, the computer of the system may comprise a stand-alone PC-type micro-computer as depicted or the computer may comprise one of a mainframe computer or a mini-computer, for example. Further still, another computer could communicate with the software program and/or computer of the system by utilizing a local area network, a wide area network, or the Internet, for example.

## Claims

1. A method for managing variable rate debt issued by a borrower, comprising:
requiring the borrower to budget for interest owed by the borrower on the variable rate debt during a time period when an interest rate on the variable rate debt is below a first predetermined low interest rate level;
requiring the borrower to apply at least a portion of any existing current budgetary excess of the borrower to reduce future interest rate risk by performing at least one of: i) the early retirement of principal associated with the variable rate debt; and ii) the funding of a sinking fund; and
requiring the borrower to apply at least a portion of any accumulated budgetary excess of the borrower during a time period when the interest rate is above a first predetermined high interest rate level to reduce an amount of debt service on the variable rate debt.

2. The method of claim 1, further comprising the step of requiring the borrower to extend a principal amortization period associated with the variable rate debt to maintain the amount of debt service below a predetermined debt service level during the time period when the interest rate is above a second predetermined high interest rate level and the impact of the performance of at least one of: i) the early retirement of principal; and ii) the application to principal and interest of amounts available in the sinking fund is not sufficient to avoid an increase in the amount of debt service above the predetermined debt service level, wherein the first predetermined high interest rate level and second predetermined high interest rate level are selected from the group of: i) different levels; and ii) the same levels.

3. The method of claim 1, further comprising the step of requiring the borrower to reduce a principal amortization period associated with the variable rate debt during the time period when the interest rate is below a second predetermined low interest rate level, wherein the first predetermined low interest rate level and second predetermined low interest rate level are selected from the group of: i) different levels; and ii) the same levels.