disincentivize small space ATX

[countvonzero]

Description

when striking a balance between minimizing PoW and user-friendliness, we have the following considerations

1. re-initializing storage has to be more expensive than storing data
2. reasonable initialization time for smeshers to join
3. doesn't cause creating many small identities

below is a proposal from @tal-m that attempts to disincentivize creating many small-unit identities.
this is proposed with the context that we cannot implement proper ATX incentives before genesis.

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Right now, IIRC, we have

ballot_weight = ATX_weight / num_ballots
proposal_reward = total_layer_reward * ballot_weight / total_layer_weight

The idea is to do this instead:

ballot_weight = ATX_weight / num_ballots
ballot_gas_cost = ATX_size * storage_gas_cost / num_ballots
proposal_reward = max(0, total_layer_reward * ballot_weight / total_layer_weight - ballot_gas_cost * ballot_gas_price)

The open questions are:

• how to set ballot_gas_price. (If we make it the same as the layer's gas price, then we might have some weird incentives -- but I haven't thought about it too deeply)
• whether/how to burn and/or distribute the storage costs for ATXs. One way to do it is to simply redistribute in the same layer:

final_proposal_reward = total_layer_reward * proposal_reward / sum_of_proposal_rewards

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[countvonzero]

ready for implementation per spec'ed in https://community.spacemesh.io/t/increase-rewards-for-large-space-atx/355/4

@pigmej

[kdonthi]

For your point about "weird incentives" are you referring to an idea where people don't participate in PoST for a layer if they feel that there are too many people participating and too many nodes to split the cake with?

Maybe a solution could be force people to stake some tokens at the beginning of a PoET round before they know how many people are going to participate?