> ## Documentation Index
> Fetch the complete documentation index at: https://docs.fincept.in/llms.txt
> Use this file to discover all available pages before exploring further.

# System regression

> Several linked regression equations estimated together: seemingly unrelated regressions (SUR/FGLS) with cross-equation constraints, three-stage least squares and system GMM for equations with endogenous regressors; residual covariance, system R² and tests of a diagonal covariance.

Toolset `panel_system`: 1 tool.

| Tool | What it does | Notes |
| - | - | - |
| `panel_system_regression` | Estimates a system of linear equations jointly: SUR (feasible GLS exploiting correlated errors, with optional cross-equation constraints), three-stage least squares or system GMM when equations have endogenous regressors. | |

Inputs, limits and outputs are described in [Fincept Panel](/guides/fincept-panel). Full schemas: `fincept_describe_tool`.


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