Are you talking about the individual level, or the mean? My estimate would be, that for the median individual, the effect will have faded out after at most 6 months. However, the mean might be influenced by the tails quite strongly.
Thinking about it for a bit longer, a mean effect of 12 years does seem quite implausible, though. In the limiting case, where only the tails matter, this would be equivalent to convincing around 25% of the initially influenced students to stop eating pork for the rest of their lives.
The upper bound for my 90% confidence interval for the mean seems to be around 3 years, while the lower bound is at 3 months. The probability mass within the interval is mostly centered to the left.
Are you talking about the individual level, or the mean? My estimate would be, that for the median individual, the effect will have faded out after at most 6 months. However, the mean might be influenced by the tails quite strongly.
Thinking about it for a bit longer, a mean effect of 12 years does seem quite implausible, though. In the limiting case, where only the tails matter, this would be equivalent to convincing around 25% of the initially influenced students to stop eating pork for the rest of their lives.
The upper bound for my 90% confidence interval for the mean seems to be around 3 years, while the lower bound is at 3 months. The probability mass within the interval is mostly centered to the left.