The point of the paragraph that the above quote was taken from is, I think, better summarised in its first sentence:
although Epoch takes an approach to forecasting TAI that is quite different to others in this space, its resulting probability distribution is not vastly dissimilar to those produced by other influential models
It is fair to question whether these two forecasts are “not vastly dissimilar” to one another. In some senses, two decades is a big difference between medians: for example, we suspect that a future where TAI arrives in the 2030s looks pretty different from a strategic perspective to one where TAI arrives in the 2050s.
But given the vast size of the possible space of AI timelines, and the fact that the two models compared here take two meaningfully different approaches to forecasting them, we think it’s noteworthy that their resulting distributions still fall in a similar ballpark of “TAI will probably arrive in the next few decades”. (In my previous post, Timelines to Transformative AI, I observed that a majority of recent timeline predictions fall in the rough ballpark of 10-40 years from now, and considered what we should make of that finding and how seriously we should take it.) It shows that we can make major changes in our assumptions but still come to the rough conclusion that TAI is a prospect for the relatively near term future, well within the lifetimes of many people alive today.
Also, I think the results of the Epoch model and the Cotra model are perhaps more similar than this two-decade gap might initially suggest. In the section where we investigated varying non-empirically-tested inputs to the Epoch model, we found that making (what seemed to be) reasonable adjustments skewed the resulting median a few decades later. (Scott Alexander also tried something similar with the Cotra model and observed a small degree of variation there.) Given the uncertainty over the Epoch model’s parameters and the scale of variation seen when adjusting them, a two decade gap between the medians from the (default versions of the) Epoch forecast and the Cotra forecast is not as vast a difference as it might at first seem.
If this seems like a helpful clarification, we can add a note about this in the article itself. :)
The point of the paragraph that the above quote was taken from is, I think, better summarised in its first sentence:
It is fair to question whether these two forecasts are “not vastly dissimilar” to one another. In some senses, two decades is a big difference between medians: for example, we suspect that a future where TAI arrives in the 2030s looks pretty different from a strategic perspective to one where TAI arrives in the 2050s.
But given the vast size of the possible space of AI timelines, and the fact that the two models compared here take two meaningfully different approaches to forecasting them, we think it’s noteworthy that their resulting distributions still fall in a similar ballpark of “TAI will probably arrive in the next few decades”. (In my previous post, Timelines to Transformative AI, I observed that a majority of recent timeline predictions fall in the rough ballpark of 10-40 years from now, and considered what we should make of that finding and how seriously we should take it.) It shows that we can make major changes in our assumptions but still come to the rough conclusion that TAI is a prospect for the relatively near term future, well within the lifetimes of many people alive today.
Also, I think the results of the Epoch model and the Cotra model are perhaps more similar than this two-decade gap might initially suggest. In the section where we investigated varying non-empirically-tested inputs to the Epoch model, we found that making (what seemed to be) reasonable adjustments skewed the resulting median a few decades later. (Scott Alexander also tried something similar with the Cotra model and observed a small degree of variation there.) Given the uncertainty over the Epoch model’s parameters and the scale of variation seen when adjusting them, a two decade gap between the medians from the (default versions of the) Epoch forecast and the Cotra forecast is not as vast a difference as it might at first seem.
If this seems like a helpful clarification, we can add a note about this in the article itself. :)