Apparently a photo of the American ambassador to China buying coffee, on his own, at a Starbucks, without relying on a lackey to fetch it for him, is making waves in China. Apparently Chinese are used to their government officials living in luxury and so seeing the American ambassador living such a normal existence is a real eye opener. Adding further shock and awe are reports of Ambassador Locke carrying his own luggage at the Beijing airport. If these reports are really causing as big of a stir as the NYTimes suggests they are, it would be interesting to know what China does about it.
One fairly unique thing about Chinese government is that it actively uses experimentation to find effective new policies. It tries out a new policy in a few provinces, and then if those policies are successful, expands them to the country as a whole. For example, the creation of special economic zones--business parks where factories are encouraged to cluster--was the result of policy experimentation.
I wonder if China will try out any policy experiments to try to improve the image of Chinese officials to make them act more like Ambassador Locke. Unfortunately, unlike special economic zones that increase rents to government officials, such an image campaign, to really be legit, would decrease rents. So unless there is a significant threat of an uprising, such image-control policies are unlikely to be implemented any time soon.
Showing posts with label experiments. Show all posts
Showing posts with label experiments. Show all posts
Thursday, August 18, 2011
Tuesday, August 16, 2011
Double-blind experiments when treatments are invasive
One of my favorite podcasts is the Nature podcast, produced by the same folks who produce the famous science journal. It's nice to have something to listen to that is fascinating and not (always) economics.
The first story of the August 11, 2011 Nature podcast reports on treating Parkinson's with an invasive technique where the skull is drilled open and new brain cells are implanted into the brain. Yet to keep such experiments "double-blind", people in the control group also experience surgery---they have a hole also drilled into their head, although unlike for the treatment group, the hole doesn't go all the way through the skull, and no new brain cells are implanted. The control group still ends up spending the same time in the surgery theater and the same gnarly bandage on their head. Both the patients and the researchers don't know who is in the treatment and who is in the control group--hence a "double-blind" experiment.
The podcasters discuss the pros and cons of this approach. However, one thing that they don't discuss is the fact that the control group does not capture the counterfactual--what would happen to a person who does not receive surgery. Rather people in the control group are receiving a somewhat invasive surgery and experiencing anesthesia, which possibly has serious health impacts, given that these are people with a severe stage of a degenerative nervous system disorder.
The whole reason for having a double blind experiment is of course that it helps researchers avoid attributing a placebo effect to a treatment effect. But when surgery for the control group is this invasive, it doesn't seem worth it, especially when the counterfactual of interest (e.g., no surgery) is not observed.
One simple way to get around this problem is to simply have 3 groups: one treatment, one control with the half-way drill surgery, and one control with no surgery. This seems like an easy extension to do, especially because the costs of the 3rd group are going to be limited to check-ups.
I wonder if the medical community may have become so focused on the gold standard of double-blind randomized experiments that they have lost focus on meaningful experiments that have easily interpretable results and that minimize harm to patients.
The first story of the August 11, 2011 Nature podcast reports on treating Parkinson's with an invasive technique where the skull is drilled open and new brain cells are implanted into the brain. Yet to keep such experiments "double-blind", people in the control group also experience surgery---they have a hole also drilled into their head, although unlike for the treatment group, the hole doesn't go all the way through the skull, and no new brain cells are implanted. The control group still ends up spending the same time in the surgery theater and the same gnarly bandage on their head. Both the patients and the researchers don't know who is in the treatment and who is in the control group--hence a "double-blind" experiment.
The podcasters discuss the pros and cons of this approach. However, one thing that they don't discuss is the fact that the control group does not capture the counterfactual--what would happen to a person who does not receive surgery. Rather people in the control group are receiving a somewhat invasive surgery and experiencing anesthesia, which possibly has serious health impacts, given that these are people with a severe stage of a degenerative nervous system disorder.
The whole reason for having a double blind experiment is of course that it helps researchers avoid attributing a placebo effect to a treatment effect. But when surgery for the control group is this invasive, it doesn't seem worth it, especially when the counterfactual of interest (e.g., no surgery) is not observed.
One simple way to get around this problem is to simply have 3 groups: one treatment, one control with the half-way drill surgery, and one control with no surgery. This seems like an easy extension to do, especially because the costs of the 3rd group are going to be limited to check-ups.
I wonder if the medical community may have become so focused on the gold standard of double-blind randomized experiments that they have lost focus on meaningful experiments that have easily interpretable results and that minimize harm to patients.
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