user263: Nothing is mentioned anywhere if, and according to which policy, IOG can move the d-“slider” in the other direction, to again start producing more centralized blocks whenever they deem this necessary. Probably a question only Charles or Duncan can answer.

user281: As long as the facility is available in the code, it is technically possible for the process to be reversed.

user67: Cardano has three different pillars of decentralization:
The first pillar: block production. Once d hit 0, this pillar was fully decentralized.
The second pillar: networking. It means how nodes find each other and pass on this information. Currently, this is a topology file and it will be replaced by P2P discovery.
The third pillar: governance. The way to vote on all protocol parameters (like d) and updates and access fundings of the treasury.
So to answer your question: yes, theoretically, it would currently be possible to increase the d-parameter again. But should IO do so, it would certainly be a disastrous signal.

263: <p>Nothing is mentioned anywhere if, and according to which policy, IOG can move the d-“slider” in the other direction, to again start producing more centralized blocks whenever they deem this necessary. Probably a question only Charles or Duncan can answer.</p>
 281: <p>As long as the facility is available in the code, it is technically possible for the process to be reversed.</p>
 67: <p>Cardano has three different pillars of decentralization:</p>
<p>The first pillar: block production. Once d hit 0, this pillar was fully decentralized.</p>
<p>The second pillar: networking. It means how nodes find each other and pass on this information. Currently, this is a topology file and it will be replaced by P2P discovery.</p>
<p>The third pillar: governance. The way to vote on all protocol parameters (like d) and updates and access fundings of the treasury.</p>
<p>So to answer your question: yes, theoretically, it would currently be possible to increase the d-parameter again. But should IO do so, it would certainly be a disastrous signal.</p>
