# Night Lights Economic Index Estimator

> Night Lights Economic Index Estimator is a paid API for AI agents from space.halowerk.com, paid per call via x402, $0.003/call, status unknown (last checked 2026-09-14).

Fits OLS regression to VIIRS/DMSP night-light radiance observations over time, converts the slope to an annual radiance change rate, and applies a caller-supplied economic elasticity to estimate an economic index change.

## Facts

- Endpoint: POST https://space.halowerk.com/v1/night-lights-econ
- Price: $0.003/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/night-lights-economic-index-estimator-9b502147
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_pC-jIF2KVmRqD441XpPs2

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability night-lights-economic-index-estimator-9b502147 -d '<json body>'
```

Example prompt: I have 10 years of mean radiance observations (2013–2022) for a region and a base economic index of 1200. Using an economic elasticity of 0.8, can you fit a regression to the radiance trend and estimate how the economic index has changed annually?

## When to prefer this

Choose this endpoint when you have multi-year time-series satellite night-light radiance data and want a quick, quantified economic proxy estimate without building your own regression pipeline. It is especially useful for regions where GDP or official economic statistics are sparse, delayed, or unreliable. Prefer it over generic regression tools when you specifically want the OLS-on-log-radiance methodology with economic elasticity scaling in a single call. Not suitable as an authoritative economic statistic or causal analysis.

## Known failure modes

- Fewer than 2 observations provided — minimum required for OLS fit
- Radiance values of zero or negative (log transform fails on non-positive inputs)
- Elasticity outside the allowed range of -10 to 10
- base_economic_index below minimum threshold (0.000001)
- Collinear or constant radiance values yielding degenerate regression
- Sensor saturation in high-luminosity urban areas causing underestimated trends
- Year values outside the valid 1900–2200 range

## How this service works

Fits ordinary least squares to log radiance by year, converts the slope to annual radiance change, and applies a caller-supplied economic elasticity. Night lights are an imperfect proxy affected by sensors, saturation, electrification, outages, policy, and conflict; this is not an official economic statistic or causal estimate.

## Output

Returns the OLS-fitted slope of log radiance over time (annual radiance change rate), the estimated annual economic index change derived by applying the caller-supplied elasticity, and likely regression diagnostics such as R-squared or confidence intervals. Comes with a caveat that night lights are an imperfect economic proxy subject to sensor artifacts, saturation, outages, and policy effects.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "observations": {
   "type": "array",
   "items": {
    "type": "object",
    "required": [
     "year",
     "mean_radiance"
    ],
    "properties": {
     "year": {
      "type": "integer",
      "maximum": 2200,
      "minimum": 1900
     },
     "mean_radiance": {
      "type": "number",
      "maximum": 1000000000000000,
      "minimum": 1e-9
     }
    },
    "additionalProperties": false
   },
   "maxItems": 1000,
   "minItems": 2
  },
  "base_economic_index": {
   "type": "number",
   "maximum": 1000000000000000,
   "minimum": 0.000001
  },
  "economic_elasticity": {
   "type": "number",
   "maximum": 10,
   "minimum": -10,
   "description": "Percent economic-index change per percent radiance change under the caller model."
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/night-lights-economic-index-estimator-9b502147/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from space.halowerk.com](https://www.zero.xyz/host/space.halowerk.com/llms.txt)