# miner_emission (/docs/hyperparameters/miner-emission)

Slot 4 of the [emission weight vector](/docs/concepts/emission-weights):
the fraction of each block's `alpha_out` that becomes miner incentive. On
subnets with several mechanisms the miner share is divided between them by
the mechanism emission split. Stored as `u64` parts of `u64::MAX`.

## How it works [#how-it-works]

Per block, `alpha_out × miner_emission` goes to the miner bucket and is paid
to miners by incentive at the epoch. If an epoch ends with zero total miner
incentive, that tempo's miner alpha is paid to validators instead of being
withheld. When a change to another slot leaves a rounding remainder, the
miner slot absorbs it so the vector sums to exactly one.

## Bounds [#bounds]

`miner_emission ≥ 0.33`. Errors: `MinerEmissionBelowMinimum`,
`EmissionWeightsDoNotSumToOne`.

## Reading and setting [#reading-and-setting]

```bash
btcli subnets emission show --netuid 12
btcli subnets emission increase --netuid 12 --slot miner --by 5%
```

Settable by the subnet owner (once per week per subnet) or root through
[`set-subnet-emission-weights`](/docs/tx/set-subnet-emission-weights); not
available on the root subnet.

## Related [#related]

* [`owner_emission`](/docs/hyperparameters/owner-emission),
  [`validator_emission`](/docs/hyperparameters/validator-emission)
* [Emission weights](/docs/concepts/emission-weights)