What is the likelihood of a PhD-holder from the USA remaining unemployed? In our country (Bangladesh), a PhD from the US is considered as a pinnacle of achievement in one's life. But, in some of my discussions in one of my previous questions I learnt that even a PhD from a US university is not enough to secure a job. 

My question is: are there any statistics on the rate of employment amongst PhD graduates trained in the US?
What is the likelihood of a PhD-holder remaining unemployed?
  
  ... I learnt that even a PhD from a US university is not enough to secure a job.


The US National Science Foundation (NSF) provides a bunch of statistics on where doctoral graduates in STEM areas (Science/Technology/Engineering/Mathematics) end up working.

This spreadsheet refers to a sampled survey done in 2008, wherein the NSF provide statistics on the employment status of all PhD graduates from STEM areas trained in the U.S.

Across all of their fields, they count 752,000 relevant graduates, of which they estimate that 651,200 were employed at that time (578,700 full-time, 72,400 part-time), 11,400 were unemployed and seeking work, 75,900 were retired, and 13,500 were not seeking work.

An unemployment rate is calculated as:

UR = UE / LF

(UR is Unemployment Rate, UE is number of people UnEmployed, LF is the number of people in the Labour Force [working or seeking work].)

So for the 752,000 U.S. trained PhD graduates considered, the NSF estimated an unemployment rate of 1.7205% in 2008.

This is compared with a U.S. unemployment rate of ~6% in mid-2008. 

So to return to your question ...


  What is the likelihood of a PhD-holder remaining unemployed?


More than three times lower than the general population (for US-trained STEM PhD holders).

Furthermore, a small percentage of unemployment is inevitable as some percentage of people will always be between jobs for a short time. (Someone more in tune with economics may be able to comment on whether or not 1.72% is close to "full employment", but being unemployed for >1.72% of your career while taking a break between jobs doesn't seem unreasonable.)

A more detailed break-down of the total size of the labour force and the unemployment rate per field follows, so if you're in a STEM area, you can pick whichever field is closest to yours.

#Field                                                    #LF      #UR

All fields                                                662,600  1.7205%

Science                                                   515,200  1.7275%

  Biological/agricultural/environmental life sciences     167,200  1.9139%   
  - Agricultural/food sciences                             17,300  1.7341%
  - Biochemistry/biophysics                                25,700  2.3346%
  - Cell/molecular biology                                 19,700  1.0152%
  - Environmental life sciences                             6,500  1.5385%
  - Microbiology                                           12,300  2.4390%
  - Zoology                                                 9,800  3.0612%
  - Other biological sciences                              76,000  1.9737%

Computer/information sciences                              16,400  1.2195%

Mathematics/statistics                                     30,300  0.9901%

Physical sciences                                         118,200  2.3689%
  - Astronomy/astrophysics                                 &gt;5,000  [Supp.]
  - Chemistry, except biochemistry                         59,600  3.0201%
  - Earth/atmospheric/ocean sciences/other phy. sci.       18,500  1.0811%
  - Physics                                                35,600  2.2472%

Psychology                                                100,500  1.2935%

Social sciences                                            82,700  1.3301%
Economics                                                  22,300  0.4484%
Political sciences                                         19,500  1.0256%
Sociology                                                  14,900  1.3423%
Other social sciences                                      26,000  2.3077%

Engineering                                               118,100  1.7782%
  - Aerospace/aeronautical/astronautical engineering       &gt;5,200  [Supp.]
  - Chemical engineering                                   14,700  2.7211% 
  - Civil engineering                                      10,500  0.9524%
  - Electrical/computer engineering                        33,800  1.1834%
  - Materials/metallurgical engineering                    12,300  2.4390%
  - Mechanical engineering                                 16,400  1.2195%
  - Other engineering                                      25,200  2.3810%

Health                                                     29,200  1.0274%

[Supp.] means suppressed: numbers are too low to preserve anonymity.




Caveats:


The context is 2008, US-trained STEM PhDs. Unemployment started increasing in 2008 with the onset of the subprime morgage crisis.
A PhD is just paperwork. What you do for your PhD is far more important than the degree itself.
Of course simply being employed is not necessarily the same as having the great job that you always wanted, and certainly we cannot infer from these data that doing a PhD is always the best path for everyone to follow their dreams.