Do any academic institutions publish objective surveys of alumni satisfaction?
Yes, here is an example.

A quantitative assessment of the 'long-term costs and benefits' is complicated by the subjective aspects of many parameters. For example, some individuals value salary over independence, other don't. But my alma mater, the Swiss Federal Institute of Technology (EPFL) does objective surveys and statistics on alumni employment. These numbers should be interpreted knowing that answers are given on a voluntary basis and, the EPFL being modest in size, n is small.

Some examples of the results (for 2011): 

"One year after graduation, MSc graduates who did not start PhD studies are employed at 90.9% by the industry in Switzerland. It took them an average of 9.5 weeks and 12 job applications to find a job (less than in 2010). Their average entry-level salary (in Switzerland) was CHF 77,967 in the private sector and CHF 76,591 in the public sector (slightly more than in 2010).

One year after PhD graduation, 90.5% of graduates have a job. However, finding a job was harder: they needed an average of 14.9 weeks and 19 job applications (significantly more than in 2010). Salaries are also lower than before, average entry-level salaries were CHF 93,716 in the private sector and CHF 82,720 in the public sector."

They also asked PhD graduates if they think their degree is 'useful for their careers':  


29% said it was mandatory, 
29% that it gave them significant advantage over non-PhDs, 
40% that it was sometimes an advantage, sometimes detrimental depending on the employer, 
4% that it gave them no advantage
whatsoever, and 
1% had no idea.


Some more data on work satisfaction of PhD graduates:

                    very high    high    average     low     very low
overall sat.        21%          54%     23%         1%      1%
interesting job     19%          51%     24%         4%      1%
adequate training   22%          41%     22%         14%     1%
degree recognition  24%          38%     28%         9%      0%
salary              8%           29%     51%         10%     1%


Here is the link to the original document (in French).

Notes: translations are mine, 1CHF=~1US$, the MSc is considered the 'undergraduate degree', global unemployment in Switzerland is &lt;4%, PhD studies are funded with a salary of roughly CHF 50'000 with negligible tuition, these are numbers for PhD in sciences and engineering, numbers for humanities are very different.