Status: RESEARCH NOTE (2026-08-11) · Program: Bitcoin Resource Accounting Companion: research/working-paper.md, research/cost-to-flood.md Source: live SCCR measurements (model-spec v2.1.0, N=32K census)
The Storage Cost Coverage Ratio, as measured on the canonical daily feed (data/sccr_history.json), is falling — from ~0.28 to 0.238 across the measured days. Transaction fees are covering less of the modeled storage cost that confirmed data imposes on the network.
| Date | Avg SCCR | Blocks sampled | Source |
|---|---|---|---|
| 2026-08-02 | 0.2243 | 153 | data/sccr_history.json |
| 2026-08-03 | 0.2840 | 137 | data/sccr_history.json |
| 2026-08-04 | 0.2611 | 159 | data/sccr_history.json |
| 2026-08-10 | 0.2379 | 145 | data/sccr_history.json |
Caveat — early series, small n. This is a 4-point series over a 9-day span with a data gap Aug 5–9 (the daily tracker was installed mid-series). The ~35% relative swing (0.28 → 0.24) is a directional signal from a young series, not a settled trend. We publish it as a live measurement with its uncertainty visible — the method and code are public so anyone can reproduce every digit. As the daily tracker accumulates clean points, the trendline will firm up.
The SCCR is the ratio of fees paid to the estimated 10-year storage cost. When it falls, the unpriced externality is growing — each block's data costs the network more relative to what the fee market pays for it.
This is the direction the paper's thesis predicts in a cooling fee market:
This is also the attacker-side implication from cost-to-flood.md: in a low-fee regime, flooding the chain gets cheaper per byte while the storage it imposes stays the same — the leverage ratio rises as fees fall.
We are not claiming this is broken. The SCCR is a measurement of a pricing gap; a falling value is the model working as intended — tracking the growing unpriced residue that the paper exists to quantify. The trend is the contribution: the externality is not static, it moves with the fee market, and right now it is moving away from coverage.
If fees keep falling and the ratio keeps dropping, at what point does the unpriced storage cost become a binding constraint on node operation? The paper's §5.4 knife-edge (the strong claim inverts at N≈49K or BTC≈$77K) and cost-to-flood.md (leverage 3.0×) bracket this — the falling trend moves along those bounds.
Published: this note, with live measurements taken every day. In progress: promotion to a research headline (Data Story / Articles) once the series firms up; the daily capture keeps running automatically.
Bitcoin Sahi Research — The Externality Is Growing (SCCR trend note), 2026-08-11.