In that case, you're talking about mining pools, which are different from miners. Individual miners participate in different mining pools, and can choose to use different pools at any time. Pool operators don't have that much control over the mining power, as miners will readily use a different pool if it's seen as a better alternative.
Historically, any time that a particular pool gets large enough to be a concern, miners switch off from using it as the risk to the network easily outweighs the small marginal benefit they may get from using a popular pool.
Miner centralization is certainly one of the primary risks in the Bitcoin network, but it's also one that's easy to overstate. Even with fairly extreme miner centralization, it's hard to come up with a good way to abuse that power without the rest of the network participants simply forking away from you.
There's good reason to think that the current level of geographic centralization in China is likely a maximum. The rapid development of ASIC hardware has kept investment timelines short as old hardware is rapidly obsolete. As hard limits in IC design are reached, this development has slowed, and may result in more competitive opportunities in other areas.
In that case, you're talking about mining pools, which are different from miners. Individual miners participate in different mining pools, and can choose to use different pools at any time. Pool operators don't have that much control over the mining power, as miners will readily use a different pool if it's seen as a better alternative.
Historically, any time that a particular pool gets large enough to be a concern, miners switch off from using it as the risk to the network easily outweighs the small marginal benefit they may get from using a popular pool.
Miner centralization is certainly one of the primary risks in the Bitcoin network, but it's also one that's easy to overstate. Even with fairly extreme miner centralization, it's hard to come up with a good way to abuse that power without the rest of the network participants simply forking away from you.
There's good reason to think that the current level of geographic centralization in China is likely a maximum. The rapid development of ASIC hardware has kept investment timelines short as old hardware is rapidly obsolete. As hard limits in IC design are reached, this development has slowed, and may result in more competitive opportunities in other areas.