Published April 2026 — Web3 Certification Board Inc.
This page documents the mathematical model, trigger logic, and design assumptions used by the Parametric Insurance Simulator. It is intended for instructors, institutional reviewers, government procurement teams, and any participant who wishes to understand how the simulation produces its outputs.
The simulator uses a weighted multi-variable risk scoring model designed to demonstrate the trigger mechanics of parametric insurance. It is not an actuarial pricing model, does not use historical loss calibration, and does not replicate the legal terms of any real insurance product. All premium amounts, payout figures, and threshold values are representative and illustrative only.
Every scenario in the simulator — from the single-variable Drought scenario to the four-variable Glacier, Pacific SIDS, and Sahel scenarios — uses the same underlying calculation pipeline:
Each variable has a trigger direction — either above a threshold (e.g., wind speed exceeding 120 km/h) or below a threshold (e.g., rainfall falling below 150 mm). The severity formula produces a value between 0 and 1, where 0 means the variable is well within safe range and 1 represents maximum recorded severity.
Each variable carries a weight that reflects its relative contribution to overall risk. Weights across all variables in a scenario sum to exactly 1.00 (100%). The weighted risk score displayed during the simulation is calculated as:
This is the number shown on the Risk Score gauge during the simulation dashboard. It is a live indicator that updates as the user adjusts sliders, before the formal simulation run begins.
Parametric insurance in real programmes typically requires a clearly defined trigger condition to be met before any payout is released. The simulator uses a majority trigger rule: a payout only occurs if at least half of the scenario's variables individually cross their respective thresholds.
For a 1-variable scenario (Drought): the single variable must trigger (1 ÷ 1 = 1.0 ≥ 0.5).
For a 2-variable scenario (Flood, Livestock): both variables must trigger (2 ÷ 2 = 1.0 ≥ 0.5).
For a 3-variable scenario (Hurricane, Heatwave, Wildfire): at least 2 of 3 must trigger (2 ÷ 3 = 0.67 ≥ 0.5).
For a 4-variable scenario (Glacier, Pacific SIDS, Sahel): at least 2 of 4 must trigger (2 ÷ 4 = 0.5 ≥ 0.5).
If the majority rule is not met, the payout is zero, regardless of how high the weighted risk score is. This models a fundamental property of parametric insurance: the trigger condition is binary and pre-agreed. It cannot be overridden by degree of suffering or subjective assessment of need — a feature that eliminates moral hazard and disputes, but also introduces basis risk when real losses occur without the index crossing the threshold.
When the majority trigger rule is satisfied, the payout is calculated directly from the weighted severity of all variables:
Where weighted severity = Σ ( severityi × weighti ) — the same value used in the Risk Score before being multiplied by 100. The payout therefore scales continuously with severity, from a small amount just above the trigger threshold up to the full maximum payout when all variables are at peak severity.
The simulator offers three coverage tiers — Basic, Standard, and Comprehensive. Each tier applies a threshold multiplier to the base trigger threshold, and sets a different maximum payout ceiling:
| Tier | Threshold Adjustment | Effect | Max Payout |
|---|---|---|---|
| Basic | Multiplier < 1.0 (typically 0.8–0.85×) | Trigger activates only during more extreme events; lower ceiling | ~60% of Standard |
| Standard | 1.0× (baseline) | Default threshold and payout as documented per scenario | Baseline (100%) |
| Comprehensive | Multiplier > 1.0 (typically 1.15–1.2×) | Trigger activates earlier (more sensitive); higher ceiling | ~150–160% of Standard |
Exact multipliers and payout ceilings vary by scenario to reflect the real-world economics of each risk type. The per-scenario variable specifications in Section 8 document the Standard tier values.
To make the model concrete, here is a step-by-step calculation for the Flood Insurance scenario using Standard coverage, with the conditions from the 2020 Kampong Luong flood used as a challenge scenario in the simulator:
Water Level severity = (4.2 − 3.5) ÷ (6.0 − 3.5) = 0.7 ÷ 2.5 = 0.28
Rainfall Duration severity = (52 − 36) ÷ (72 − 36) = 16 ÷ 36 = 0.44
(0.28 × 0.60) + (0.44 × 0.40) = 0.168 + 0.176 = 0.344
0.344 × 100 = 34%
Both variables triggered (4.2 > 3.5 ✓, 52 > 36 ✓). Triggered: 2 ÷ 2 = 1.0 ≥ 0.5 ✓
round($5,000 × 0.344) = $1,720
This illustrates a key characteristic of the model: even with both variables clearly above their thresholds, the payout is $1,720 — not the full $5,000. The full maximum payout is only reached when both variables simultaneously hit the top of their respective ranges (water level at 6.0 m and duration at 72 hours).
The table below documents the Standard tier trigger parameters for all nine scenarios. Click any scenario to expand its full variable specification.
Understanding what the simulator does not model is as important as understanding what it does. The following simplifications are intentional and appropriate for an educational tool:
Real parametric programmes set their trigger thresholds and maximum payouts through actuarial modelling of historical loss data — typically 20–50 years of event records correlated with insured losses. The simulator uses representative threshold values chosen to reflect real programme designs (e.g., IBLI's NDVI threshold in Marsabit, CCRIF's wind speed parameters) but does not replicate the underlying statistical models. The Policy Design Lab does, however, calibrate against a curated set of real historical events with documented loss outcomes (see Section 10) so that the basis-risk analysis is grounded in actual occurrences rather than hypotheticals.
Premiums in the simulator are illustrative. Real premiums are priced from the expected annual payout (probability of trigger × average severity) plus reinsurance costs, expenses, and a risk margin. The simulator does not model probability distributions or return periods.
Real programmes typically transfer risk to reinsurance markets or catastrophe bond investors. The simulator treats the insurer as a single entity with unlimited capacity — sufficient for demonstrating trigger mechanics but not capital structure.
The severity formulas use linear interpolation between the threshold and the range boundary. Real programmes may use non-linear severity curves — for example, doubling the payout acceleration beyond a certain level of wind speed — to better reflect how physical damage scales with hazard intensity.
The public scenarios demonstrate basis risk conceptually — showing cases where the index does not trigger despite real losses. The Policy Design Lab goes further: its Basis Risk Explorer classifies a curated set of real historical events into a confusion matrix (covered losses, missed losses, false alarms, and correct non-payments) and reports detection rate, miss rate, and false-alarm ratio for any threshold configuration. These figures are computed over the curated event set rather than a complete spatial loss census, so they are indicative measures of the design trade-off — not a programme-grade basis-risk certification.
In real parametric programmes, the data pipeline from measurement to payout is critical for trust. Each scenario in the simulator is modelled on data sources used in operational programmes:
| Scenario | Real Data Source Basis | Real Programme Reference |
|---|---|---|
| Drought | CHIRPS (Climate Hazards Group InfraRed Precipitation with Station data) | ACRE Africa, Kilimo Salama (Kenya/Ethiopia) |
| Flood | River sensor networks + satellite SAR imagery | WFP Forecast-based Financing (Bangladesh, Cambodia) |
| Hurricane | NOAA National Hurricane Center wind speed records | CCRIF SPC (Caribbean, since 2007) |
| Heatwave | WMO wet-bulb temperature station data | Ahmedabad Heat Action Plan; India National Heat Action Programme |
| Wildfire | EPA AQI monitoring network + NASA FIRMS fire detection | Emerging US/Australian state-level parametric smoke programmes |
| Glacier | ESA CryoSat-2, GRACE-FO satellite + WMO glacier inventory | Emerging slow-onset L&D instruments; GCF feasibility pilots |
| Livestock (IBLI) | MODIS Terra/Aqua NDVI + CHIRPS precipitation anomaly | IBLI (Marsabit County, Kenya; Borana Zone, Ethiopia) — ILRI/Cornell |
| Pacific SIDS Ocean Coverage | NASA/CNES altimetry (TOPEX, Jason-3) + Argo ocean floats + NOAA tide gauges + satellite reef spectral analysis | PCRAFI (Pacific Catastrophe Risk Assessment and Financing Initiative); AOSIS Loss & Damage proposals; GCF SIDS access pathways |
| Sahel Multi-Year Drought | Africa Risk View (ARV) satellite rainfall + CHIRPS + MODIS/Sentinel-2 NDVI + FEWS NET IPC food security assessments | African Risk Capacity (ARC) — member states including Niger, Mali, Senegal; Sahel Alliance multi-year drought instruments |
The Policy Design Lab's historical event set and Basis Risk Explorer draw on the specific datasets below. Each entry documents the dataset, version, provider, native resolution, baseline period, and a formal citation so that every calibrated value is traceable to its source.
| Scenario | Dataset & Version | Provider / Institution | Resolution | Baseline | Citation |
|---|---|---|---|---|---|
| Drought | CHIRPS — Climate Hazards Group InfraRed Precipitation with Station data (v2.0) | Climate Hazards Center, UC Santa Barbara (CHC/UCSB) | 0.05° (~5 km); Daily, pentadal, dekadal, monthly, seasonal | 1981–2010 climatological mean (record from 1981–present) | Funk, C. et al. (2015). The climate hazards infrared precipitation with stations. Scientific Data 2, 150066. https://www.chc.ucsb.edu/data/chirps |
| Flood | River-stage gauges + satellite flood mapping (Copernicus Sentinel-1 SAR / EMS, Dartmouth Flood Observatory) (Copernicus EMS Rapid Mapping; DFO event archive) | National hydro-meteorological services; Copernicus Emergency Management Service (ECMWF/EC); Dartmouth Flood Observatory | Gauge point; ~10–20 m SAR flood extent; Sub-daily gauge readings; per-event satellite acquisition | Local alert-level stage (3.5 m reference) per national hydromet standards | Copernicus Emergency Management Service (EMS) flood mapping; Brakenridge, G.R., Dartmouth Flood Observatory event archive. https://emergency.copernicus.eu/ |
| Hurricane | NOAA HURDAT2 best-track + parametric wind/surge index (CCRIF SPC model) (HURDAT2 (Atlantic); CCRIF SPC parametric products) | NOAA National Hurricane Center; Caribbean Catastrophe Risk Insurance Facility (CCRIF SPC) | Track point + modelled wind/surge footprint; 6-hourly best-track fixes | Saffir–Simpson category thresholds; CCRIF index calibration | Landsea, C.W. & Franklin, J.L. (2013). Atlantic Hurricane Database Uncertainty (HURDAT2). Mon. Wea. Rev. 141. https://www.nhc.noaa.gov/data/ |
| Heatwave | ERA5 reanalysis — wet-bulb temperature & heat duration (ERA5 (C3S)) | ECMWF / Copernicus Climate Change Service (C3S) | 0.25° (~31 km); Hourly (1940–present) | 1991–2020 climatology | Hersbach, H. et al. (2020). The ERA5 global reanalysis. Q. J. R. Meteorol. Soc. 146, 1999–2049. https://cds.climate.copernicus.eu/ |
| Wildfire | Air Quality Index (ground PM2.5 monitors) + NASA FIRMS active fire (MODIS/VIIRS) (FIRMS MODIS C6.1 / VIIRS) | NASA FIRMS / LANCE; national air-quality monitoring networks | 375 m (VIIRS) / 1 km (MODIS) active fire; monitor-point AQI; Near-real-time (multiple daily passes) | US EPA AQI breakpoints (PM2.5) | NASA FIRMS (Fire Information for Resource Management System); US EPA AQI methodology. https://firms.modaps.eosdis.nasa.gov/ |
| Glacier | Satellite glacier mass-balance + snowpack / streamflow gauges (GLOF monitoring) (Hugonnet et al. (2021) geodetic mass balance; national snow/hydro networks) | Randolph Glacier Inventory community; national hydrological services (Andes) | ~100 m DEM differencing; basin-scale hydrology; Annual / seasonal | 2000–2019 geodetic baseline | Hugonnet, R. et al. (2021). Accelerated global glacier mass loss in the early twenty-first century. Nature 592, 726–731. https://doi.org/10.1038/s41586-021-03436-3 |
| Livestock (IBLI) | MODIS Vegetation Indices (NDVI) + CHIRPS rainfall (MOD13Q1 V061 (NDVI); CHIRPS v2.0 (rainfall)) | NASA LP DAAC (MODIS); CHC/UCSB (CHIRPS); IBLI programme by ILRI | 250 m (MOD13Q1 NDVI); 16-day composite (2000–present) | NDVI long-term seasonal mean; IBLI strike at ~20th–25th percentile | Didan, K. (2021). MOD13Q1 MODIS/Terra Vegetation Indices 16-Day L3 Global 250m V061. NASA LP DAAC. DOI:10.5067/MODIS/MOD13Q1.061 https://doi.org/10.5067/MODIS/MOD13Q1.061 |
| Pacific SIDS Ocean | Satellite altimetry sea level + NOAA Coral Reef Watch + tide gauges + wave model (C3S sea-level; NOAA CRW Degree Heating Weeks; PCRAFI) | Pacific Catastrophe Risk Assessment & Financing Initiative (PCRAFI); NOAA Coral Reef Watch; Copernicus C3S | ~0.25° altimetry; 5 km coral bleaching; gauge-point salinity; Daily–monthly | Satellite-era mean sea level; CRW bleaching thresholds | NOAA Coral Reef Watch; PCRAFI (World Bank / SPC). Copernicus Marine / C3S sea-level products. https://coralreefwatch.noaa.gov/ |
| Sahel Multi-Year Drought | Africa RiskView (WRSI rainfall) + CHIRPS + MODIS NDVI (Africa RiskView (ARC); CHIRPS v2.0; MOD13Q1 V061) | African Risk Capacity (ARC); CHC/UCSB; NASA LP DAAC | ~5 km rainfall; 250 m NDVI; Dekadal / seasonal | WRSI long-term mean; ARC return-period calibration | African Risk Capacity (ARC) — Africa RiskView technical framework; CHIRPS (Funk et al. 2015). https://www.arc.int/ |
Index values for named events are calibrated to the documented severity of each event (for example, a drought season expressed as a percentage of the long-term mean rainfall in the cited dataset). Where an independently verifiable gridded cell value is not available, a representative figure consistent with the cited dataset and event is used and labelled as such in the Lab. Annual probabilities shown in the Lab are indicative inputs to the premium model derived from each dataset's historical distribution or documented return periods — they are illustrative, not actuarial rates.
In smart contract implementations, a data oracle is the service that feeds verified, tamper-resistant data from these external sources into the on-chain trigger logic. The oracle acts as the trusted bridge between the physical world and the automated payment system — its integrity is what makes parametric insurance trustworthy without requiring a loss assessor.
When the user clicks "Run Simulation," the simulator progresses through six phases designed to mirror the sequence a real smart contract would execute. Each phase is presented with a time delay to create a realistic representation of the verification pipeline:
The blockchain transaction record generated during the simulation — including hash, block number, timestamp, and all variable values — is illustrative of the on-chain audit trail that makes parametric payouts verifiable and dispute-free.
The Parametric Insurance Simulator is a training tool produced by the Web3 Certification Board Inc. (W3CB) for use in policy training programmes, university courses, and professional development contexts. The simulation model, scenario parameters, and all associated content may be cited in academic and policy work with attribution to W3CB.
Outputs from the simulator — including payout calculations and risk scores — are not evidence of insurability, actuarial soundness, or real programme performance. No reliance should be placed on simulator outputs for actual insurance decision-making. See the Terms of Use and regulatory disclaimers in the application footer.
Questions regarding the simulation model or requests to license the methodology for training programme development should be directed to the Web3 Certification Board Inc.