Actually, this has been done as a result of
MMR withdrawal in Japan and autism rates actually increased after MMR was no longer given.
Tough luck Clay.
ETA: Eventually the monovalent vaccines were used and mumps and rubella incidence has gone up steadily since the withdrawal of MMR due to changes in vaccine recommendations.
Este
There's also the studies discussed here:
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2908388/ which address both rates of autism and age of onset.
"...investigators did not observe a clustering of autism diagnoses relative to the time that children received MMR vaccine, nor did they observe a difference in age at autism diagnosis between those vaccinated and not vaccinated or between those vaccinated before or after 18 months of age"
"...an increase in autism diagnoses despite stable MMR vaccination rates"
"...the increase in the number of autism diagnoses did not correlate with MMR vaccination rates"
"Autism rates increased coincident with a decrease in MMR vaccination rates."
"Of 309 children hospitalized for autistic disorders, no clustering occurred relative to the time of MMR vaccination."
"The authors observed no differences in the relative risk of autism between those who did and those who did not receive MMR vaccine. Among autistic children, no relationship between date of vaccination and development of autism was observed."
"The authors observed no differences in age at vaccination between autistic and nonautistic children, which suggests that early age of MMR vaccine exposure was not a risk factor for autism."
Clayton doesn't seem to understand the the questions he's seeking answers to have already been asked and answered by researchers. If he bothered to actually look at the evidence which is constantly spoon-fed to him on this thread he'd be well-aware of the research that has already been conducted: research that renders his proposed study redundant. He probably won't read what I'm about to post, either.
http://www.sciencebasedmedicine.org/index.php/the-early-course-of-autism/
Prior studies using home movies have shown that signs of autism can be detected between 8-12 months.
A study looking at head circumference found statistical differences prior to 12 months. And
one study looking at movements found differences between 4-6 months. So it seems the consensus of current evidence is that objective and detectable signs of autism emerge between 6-12 months. This study does not support detection prior to 6 months, but other studies do suggest this might be possible.
I do wonder what Clayton might make of the claim that "the consensus of current evidence is that objective and detectable signs of autism emerge between 6-12 months" in light of the US vaccination schedule. I won't expect him to click on any links I provide, but I will point out that MMR, according to the schedule, should be given at 12-15 months.
http://www.cdc.gov/vaccines/parents/downloads/rec-iz-babies.pdf