Inflation, Debt and Leverage: The Funding Assumptions That Can Break a Business Case

Financing does not merely fund a project; it changes the project's risk profile and the enterprise's capacity to survive adverse outcomes.

A business case can be operationally sound and still become financially fragile because the funding assumptions were treated as background detail. Inflation changes input costs and purchasing power. Interest rates change debt-service requirements. Fixed and variable borrowing distribute risk differently. Repayment timing changes liquidity. Leverage can increase returns when outcomes are favourable and magnify losses when they are not.

The supplied study notes on external uncertainties emphasise all of these mechanisms. They also make an important point that is easy to miss: forward estimates should state explicitly how inflation has been included or excluded. The strategic issue is consistency between the economic model, financing structure and the environment the project must survive.

The Strategic Context

Projects are often evaluated using operating forecasts and then financed through a separate treasury or funding process. That separation can obscure interaction.

A long-duration project may face construction-cost inflation before benefits begin. A variable-rate facility can increase financing cost at the same time demand weakens. A heavily leveraged project can meet expected return targets while leaving little room for schedule delay. A government or not-for-profit project may not seek profit, yet still face real constraints from inflation, borrowing cost and funding timing.

Funding therefore influences more than the discount rate. It affects resilience, flexibility and the amount of strategic room available when reality differs from the plan.

What Leaders Commonly Misread

The first misreading is to treat inflation as a single percentage applied uniformly. Labour, energy, specialised equipment, property, freight and customer prices may move differently. What matters is the mismatch between cash inflows and cash outflows, not an abstract economy-wide average.

The second is to assume that fixed-rate debt is inherently safer. Fixed rates provide cost certainty but may become expensive relative to market if rates fall. Variable rates preserve exposure to prevailing market conditions but create uncertainty in future interest expense. The correct choice depends on the project's cash-flow profile, risk appetite and the value placed on certainty.

The third is to focus on expected return without examining liquidity. A project can be economically valuable over its full life and still create a cash crisis if funding requirements arrive before cash inflows or refinancing becomes unavailable.

The fourth is to celebrate leverage because it increases return on equity in favourable scenarios. The supplied study notes correctly emphasise the other side: leverage also amplifies downside. The numerical example in those notes contains internal inconsistencies and should not be reproduced without recalculation. [FACT CHECK REQUIRED]

Reframing the Issue

The financing question should not be 'What is the cheapest source of capital?' It should be 'What funding structure allows the organisation to capture the opportunity while remaining resilient across credible adverse scenarios?'

That changes the optimisation target. Lowest expected financing cost may not be best if it creates unacceptable refinancing, covenant, interest-rate or liquidity risk.

The relevant enterprise outcomes include cost of capital, cash-flow resilience, ownership flexibility, balance-sheet capacity and the ability to continue funding other strategic initiatives.

Strategic Analysis: Four Financing Exposures

Inflation exposure

Inflation can increase project cost, operating expenditure and financing needs. It can also affect revenue, though not always at the same rate or with the same timing. Leaders should distinguish nominal cash flows from real purchasing-power effects and ensure assumptions are internally consistent.

The supplied notes acknowledge that long-range inflation estimation is uncertain. That is precisely why major business cases should not hide inflation inside a single deterministic assumption. Where the exposure is material, test alternative inflation paths.

Interest-rate exposure

Fixed, floating and hybrid borrowing structures distribute interest-rate risk differently. The strategic decision should consider how much cash-flow variability the enterprise can tolerate and whether rate movements are likely to correlate with other project pressures.

Refinancing and maturity exposure

Interest-only structures can reduce near-term cash requirements but leave principal repayment or refinancing concentrated later. Principal-and-interest structures reduce the outstanding balance progressively but require larger ongoing cash payments. Neither is universally preferable.

The critical issue is whether the repayment architecture matches the asset's cash-generation pattern and the organisation's future funding capacity.

Leverage exposure

Borrowing allows organisations to undertake investments beyond what internal funds alone would permit. That can accelerate growth or public-service delivery. It also creates fixed obligations that do not disappear when project performance weakens.

Leverage should therefore be assessed against downside cash flow, not only expected return.

Decision Framework

A funding review for a major project should test seven conditions.

For material investments, leaders should examine at least a base, adverse and severe-but-plausible funding scenario. The objective is not to predict interest rates precisely. It is to discover where the capital structure stops being resilient.

A further discipline is to separate project viability from financing viability. A good asset financed badly can still create enterprise distress. Conversely, a cheap financing package cannot rescue a structurally weak investment.

Related article: Risk Is a Distribution, Not a Number

From Strategy to Execution

Immediately, require business cases to state whether values are nominal or real and how inflation has been treated. Eliminate silent mixing of assumptions.

Next, include financing in scenario analysis. If construction slips twelve months, what happens to interest during construction, refinancing timing and cash requirements? If input inflation rises but customer pricing is delayed, what happens to liquidity?

At portfolio level, model aggregate funding exposure. Several projects may independently appear financeable while collectively creating a maturity wall, interest-rate concentration or excessive dependence on the same funding source.

Longer term, create governance that links treasury, strategy, risk and project investment decisions early. Funding should shape project design before commitment, not simply be arranged after the organisation has decided it wants the project.

Signals to Monitor

Watch for frequent increases in approved funding without corresponding changes to the original economic case; projects whose benefits remain constant while inflation assumptions change only on the cost side; rising variable-rate debt alongside deteriorating operating margins; refinancing concentrated in the same period across several investments; and funding decisions that consume balance-sheet capacity needed for higher-priority initiatives.

Another warning sign is when the funding model is owned by one function and the operational business case by another, with no single forum testing whether the assumptions remain coherent.

Questions for the Leadership Team

1. Which project assumptions are most exposed to inflation mismatch rather than inflation itself?
2. What happens to liquidity if schedule, rates and operating performance deteriorate at the same time?
3. How much refinancing risk are we accepting, and what would make that market unavailable?
4. Are we using leverage to fund genuine value creation or to make a marginal equity return appear attractive?
5. What balance-sheet capacity will remain after this project is funded?
6. Which financing risks are correlated across the rest of the portfolio?

Closing Perspective

Capital structure is part of project strategy. The funding decision determines who carries risk, when cash is required and how much room the organisation retains when conditions change.

Leaders should therefore judge financing by more than expected cost. The stronger question is whether the proposed structure allows the enterprise to remain solvent, flexible and capable of funding its priorities when the future is less favourable than the business case assumed.

Source Foundations

• MPM416 External Uncertainties — Inflation and Sources of Funds (supplied course material).