The Subsidy Feedback Loop: How Rupiah Weakness and Hormuz Oil Costs Turn the 2027 Budget Into Currency Risk

Rupiah Stability Watch · 2026-07-28

The premise

Indonesia’s currency problem is no longer only a market-screen story. It is also becoming a budget story.

On 23 July 2026, Bank Indonesia’s JISDOR reference rate stood at Rp17,915 per US dollar, above the Rp16,800–Rp17,500 exchange-rate range agreed in the 2027 macro framework. Brent crude also touched $100 a barrel, according to the New York Times, as the US-Iran conflict continued to disturb Middle East energy flows. Those two prices — the dollar and oil — sit directly inside Indonesia’s subsidy arithmetic.

The fiscal signal is already visible. Databoks, citing the Ministry of Finance, reported that subsidy and compensation spending reached Rp203.7 trillion by end-May 2026, equal to 45.6 percent of the full-year ceiling and up 208.2 percent year-on-year. It said Rp108.9 trillion of that was compensation spending and Rp94.8 trillion was subsidy spending. VOI later reported that by the first half of 2026, subsidy and compensation realization had reached Rp233 trillion, or 52.1 percent of the state-budget ceiling, with both subsidies and compensation around Rp116 trillion each.

That does not mean a crisis is inevitable. Indonesia still has a deficit rule, a large domestic bond market, an active central bank, and a record of absorbing energy shocks through the budget. It does mean the rupiah channel has changed. If fuel and electricity prices are held stable while oil and the dollar rise, households are protected first at the pump. The cost then reappears elsewhere: in the deficit, in debt issuance, in budget trade-offs, in the sovereign risk premium, and eventually in borrowing costs faced by households and firms.

This piece builds on Rupiah Stability Watch’s prior work on the twin oil squeeze, war-risk insurance, the Strait of Hormuz toll regime, the double terms-of-trade squeeze, MBG fiscal cost and the rupiah, the August Bank Indonesia policy outlook, and the July 21 Weekly Rupiah Monitor. It also uses MBG Watch’s fiscal-displacement work as a sister warning from the spending side. The point here is narrower: how a subsidy overrun can become a currency feedback loop.

What the evidence supports

The first supported claim is that the 2026 subsidy bill is running hot.

The May number implies a full-year subsidy-and-compensation ceiling near Rp447 trillion: Rp203.7 trillion divided by 45.6 percent. The first-half number implies almost the same ceiling: Rp233 trillion divided by 52.1 percent. The details matter because this is not a small line item. It is a budget component large enough to alter the way investors read fiscal space.

The second supported claim is that the main drivers are exactly the variables now under pressure. Databoks reported that the Ministry of Finance attributed the realization to Indonesian Crude Price movements, rupiah depreciation, fertilizer subsidy advances, and higher volumes of subsidized fuel, LPG, and electricity. VOI reported a similar explanation from Finance Minister Purbaya Yudhi Sadewa: ICP, the rupiah, and higher subsidized fuel, LPG, electricity, and fertilizer volumes all pushed spending higher.

The third supported claim is that the 2027 framework already contains a narrow tolerance band. Detik reported that the government and the House’s Commission XI agreed a 2027 deficit range of 1.80–2.40 percent of GDP, revenue of 12.01–12.40 percent of GDP, a 10-year SBN yield assumption of 6.5–7.3 percent, and an exchange-rate assumption of Rp16,800–Rp17,500 per dollar. Kontan and other outlets reported that the 2027 Indonesian Crude Price range was set at $70–$95 per barrel. A Rp17,915 JISDOR and $100 Brent do not by themselves break a budget. They do show that the stress case is no longer remote from the planning range.

The fourth supported claim is that fiscal credibility is already part of rupiah pricing. Antara reported that the rupiah strengthened on 21 July after investor worries over the fiscal outlook eased, with the first-half deficit at Rp196.5 trillion, or 0.76 percent of GDP, and the 2026 deficit target still below the 3 percent ceiling. The same Antara account noted that market concern had grown in prior months, with some projections reportedly putting the deficit as high as 4 percent of GDP. That is the channel: the rupiah is not only reacting to oil import demand. It is reacting to whether investors believe the budget can absorb the shock without eroding fiscal discipline.

The arithmetic is large enough to matter

The cleanest conservative sensitivity comes from Indonesia’s own reported shock estimate. Reuters reported in April that Indonesia estimated up to $5.9 billion of additional energy subsidy needs due to the Iran war, while the 2026 budget assumed a $70 ICP and Rp16,500 per dollar. At the 23 July JISDOR of Rp17,915, $5.9 billion is about Rp105.7 trillion. If read as a rough $30-per-barrel stress from $70 toward $100, the implied order of magnitude is about Rp35 trillion for each $10-per-barrel oil move.

A separate currency sensitivity is mechanical and should be treated cautiously. If the reported Rp381.3 trillion energy-support envelope is dollar-linked in proportion to the exchange rate, every Rp1,000 depreciation from Rp16,500 adds about Rp23 trillion. The move from Rp16,500 to Rp17,915 is Rp1,415, implying about Rp32.7 trillion of added pressure on that envelope before volume changes, timing lags, or administered-price decisions.

Put together, a simple stress case — oil from $70 to $100 and the rupiah from Rp16,500 to Rp17,915 — points to roughly Rp138 trillion of additional pressure against the original energy-support arithmetic. That is not a forecast. It is a scale marker. It says the shock is large enough to compete with major discretionary programs, with capital spending, or with the intended deficit path.

This also helps interpret MBG Watch’s sister finding that a sustained Hormuz conflict could push the 2027 fuel-subsidy requirement toward Rp275–300 trillion. That estimate is not the same as total subsidy and compensation spending. But it is directionally consistent with the currency-side point: if imported energy costs and the dollar rise together, the subsidy line becomes a macro variable, not only a social-protection instrument.

Two channels, not one

The current-account channel is the first channel. More expensive oil and war-risk insurance raise the dollar cost of imports. Even if volumes do not change, Indonesia needs more foreign exchange to buy the same energy. This was the core of our earlier work on the twin oil squeeze, war-risk insurance, the Hormuz toll regime, and the double terms-of-trade squeeze. The current-account effect is direct: more dollars needed for energy, shipping, and insurance.

The fiscal-risk-premium channel is different. The government can prevent the oil shock from appearing in retail fuel and power prices. That protects households from an immediate inflation spike. But the budget then absorbs the difference through subsidies and compensation to state-owned enterprises. If the bill rises without offsetting revenue, reform, or reprioritization, investors may ask whether the deficit target still holds and whether bond supply will rise.

That question can feed back into the rupiah through several mechanisms. Higher expected bond supply can push SBN yields higher. Higher yields may attract some carry-seeking flows, including into Bank Indonesia rupiah securities, but they also signal tighter financial conditions. If inflows are short-duration carry rather than long-horizon real-money allocation, the exchange-rate support is less stable. Bank Indonesia then faces a narrower policy corridor: it can defend the rupiah with rates and liquidity instruments, but doing so raises domestic borrowing costs and can slow credit.

This is why the loop matters. Rupiah weakness raises the subsidy bill. A larger subsidy bill can raise fiscal-risk perception. Higher risk perception can weaken the rupiah or force higher yields. Higher yields and a weaker currency then make the next round of subsidy arithmetic harder.

The human impact is delayed, not absent

Fuel subsidies are often described as shielding people from price increases. That is partly true. A driver, a fisherman, a food-stall owner, or a commuter may not see the full oil-price shock at the pump.

But insulation is not elimination. Someone still pays.

If the budget pays, the cost can show up as a higher deficit, higher interest expense, or smaller space for other services. If state-owned enterprises wait for compensation, the cost can show up as pressure on their balance sheets and investment plans. If Bank Indonesia tightens to support the rupiah, the cost can show up as more expensive working capital, mortgages, motorcycle loans, and business credit. If the rupiah still weakens, the cost can show up in imported food, fertilizer, medicines, spare parts, and logistics.

For poorer households, the difference between direct and indirect pass-through matters. A subsidized liter of fuel may remain affordable while food, school transport, and credit become harder. The policy question is therefore not whether to care about pump prices or fiscal discipline. The question is how to see both at once.

What the evidence does not support

The evidence does not support a simple claim that the rupiah must weaken. Indonesia has tools. Bank Indonesia held the BI-Rate at 5.75 percent in July after raising it in June, according to CNBC Indonesia and Bank Indonesia’s June release. Antara has also reported that foreign inflows into SRBI helped stabilize the currency earlier in June. If oil retreats, if capital inflows broaden, or if the budget draft credibly absorbs the shock, the loop can loosen.

The evidence also does not support treating all subsidy spending as waste. Subsidies and compensation can prevent sudden hardship and reduce second-round inflation in transport and food. For a government facing an external shock, smoothing can be a legitimate stabilization choice.

Nor does the evidence support ignoring the distributional risk. Fast administered-price reform can reduce fiscal pressure but raise household costs. Full budget absorption can protect households now but shift the burden to future taxes, lower services, or higher borrowing costs. The least-harm reading is not one instrument. It is a transparent accounting of where the cost is being placed.

Signposts to watch

The first signpost is the oil-rupiah pair, not either variable alone. A $100 oil price with a stable rupiah is different from a $100 oil price with renewed rupiah depreciation. The combined price is what determines the rupiah value of imported energy.

The second signpost is the subsidy-and-compensation realization path. The May and first-half figures suggest a fast run-rate. If monthly realization slows, the fiscal-risk channel weakens. If it accelerates into the 2027 budget process, the channel strengthens.

The third signpost is the composition of capital flows. SRBI inflows can help stabilize the exchange rate, but durable support is stronger when it includes longer-horizon bond and equity allocation rather than only high-yield short instruments.

The fourth signpost is the 2027 budget draft. The question is not only the headline deficit. It is whether priority spending is protected without relying on optimistic oil, exchange-rate, or revenue assumptions.

The fifth signpost is the SBN yield curve. If yields rise because US yields rise, the rupiah implication is different from yields rising because investors demand a larger Indonesia-specific fiscal premium.

What would falsify this concern

Several developments would weaken the feedback-loop thesis.

Brent could retreat decisively and stay below the upper end of the 2027 ICP range. The rupiah could return inside the Rp16,800–Rp17,500 planning range on the back of broad, real-money capital inflows rather than only carry-sensitive SRBI flows. The 2027 budget draft could protect priority spending while keeping the deficit within the agreed 1.80–2.40 percent range using credible revenue and expenditure assumptions. Subsidy reform could change the pass-through formula in a way that lowers fiscal exposure without a sharp welfare shock. Energy-import volumes could fall through efficiency, substitution, or lower demand.

If those things happen together, the subsidy bill remains a budget item, not a currency feedback loop.

The least-harm reading

Indonesia’s choice is not between protecting households and protecting the rupiah. A weak rupiah eventually reaches households too.

The least-harm reading is to make the cost visible early. If the state chooses to absorb oil and currency shocks through subsidies, the budget should show where the money comes from, what spending is protected, what assumptions are being used, and how the risk changes if oil or the rupiah moves again. If the state chooses to reduce exposure, the distributional effect should be named before households feel it.

The rupiah is a price, but it is also a signal. In this setting, it is signaling whether Indonesia can keep energy protection, fiscal credibility, and monetary room in balance. The answer is not fixed. It will be written in the next subsidy realization, the next budget draft, and the next round of capital-flow data.

Sources