which one is better, with respect to academics, ranking and placements?
UCR is ranked higher and since it is in Southern California and closer to large metropolitan areas, job placement should be better. UCM is a very nice campus but not an ideal location in the Central valley. I would not take anyone’s word at face value but you should visit both to form your own opinions.
I have heard UC Merced has some good undergrad research opportunities. Being a new campus, they have state of the art technology and not many grad students to do research. So perhaps certain majors (sciences or ??) would work out well at Merced.
But indeed, UCR is ranked higher.
In addition, UCR has a wider selection of majors. For example, UCR has a wider selection of engineering majors in addition to a business degree, both, which UCM does not have. Additionally, UCR has a medical school which opened around 2013. The medical school will only enhance the school’s prestige. You might also want to go to each school’s website to see which majors are available in each school and determine what you would want to study.
In further support of the above comments: at UCR the average SAT is reported to be 1685 and the average ACT is 24, and at UCM the average SAT is 1520 and the average ACT is 22, according to http://colleges.startclass.com
It seems as if the UCR students are academically similar to those at UC Santa Cruz, which has avg SAT reported as 1685 (same) and ACT 26 (higher).