Large-scale conspiracies would quickly reveal themselves

Not enough 1984 nor brave new world background. You don't need to be part of the conspiracy to work in leak control. Once you have an censoring organization to prevent leaks, and a media control to diminish/deny/joke about leaks that happened, that don't need to be part of the conspiracy, the dynamics can be different.

Think how many climate change denialists actually believe what they say vs the amount of that are aware of being paid but have a reasonable doubt about if is true or not, vs the actual conspiracy. You can have a big conspiracy with big numbers of participants but a relatively small amount people that actually knows the truth. And that small amount of people could have a control layer above them (that don't know the truth neither)

The article says that only "Three genuine conspiracies" where used to estimate his model. That seems like a very small sample to me.

Uhm. HELLO?! That's what they WANT us to think.

Perhaps people that talk about climate change hoax and accuse the scientist of being part of a great conspiracy must read this study

I wonder if the author could test the model against the Snowden leak -- how many people knew vs the time it took to leak.