Correlational finding on Happiness and subject: Kind of occupation (profession)

StudyDeVoe & Pfeffer (2009): study US 2002
TitleWhen Is Happiness About How Much You Earn? The Effect of Hourly Payment on the Money-Happiness Connection.
SourcePersonality and Social Psychology Bulliten, 2009, Vol. 12, 1602 - 1618
PublicWorking people, USA, 2002
SampleProbability stratified sample
Respondents N =15450

Author's labelOccupation
Page in Source 1607
Our classificationKind of occupation (profession)
Self report on job, coded by interviewer
a: manegerial, professional (reference)
b: technical, sales, administrative support
c: service
d: farming, forrestery, fishing
e: precision production, crafsts, repair
f: operators, fabricators, laborers
Observed distributionM = a: 0.33, b: 0.28, c: 0.15, d: 0.01, e: 0.10, f: 0.11 SD = a: 0.47, b: 0.45, c: 0.36, d: 0.10, e: 0.29, f: 0.32

Observed Relation with Happiness
O-HL-c-sq-v-4-fr=+.09 p < .05
a: manegerial, professional         (vs not)
O-HL-c-sq-v-4-fr=+.01 ns
b: technical, sales, administrative  
(vs manegerial)
O-HL-c-sq-v-4-fr=-.07 ns
c: service                           
(vs manegerial)
O-HL-c-sq-v-4-fr=-.02 ns
d: farming, forrestery, fishing      
(vs manegerial)
O-HL-c-sq-v-4-fr=-.03 ns
e: precision production, crafsts, repair 
(vs manegerial)
O-HL-c-sq-v-4-fr=-.05 ns
f: operators, fabricators, laborers 
(vs manegerial)

Appendix 1: Happiness measures used
CodeFull Text
O-HL-c-sq-v-4-fSelfreport on single question:

If you were to consider your life in general these days, how happy or unhappy would you say you are, on the whole...?
4 very happy
3 fairly happy
2 not very happy
1 not at all happy

Appendix 2: Statistics used
rPRODUCT-MOMENT CORRELATION COEFFICIENT (Also "Pearson's correlation coefficient' or simply 'correlation coefficient')
Type: test statistic.
Measurement level: Correlate: metric, Happiness: metric
Range: [-1; +1]

r = 0 no correlation ,
r = 1 perfect correlation, where high correlate values correspond with high happiness values, and
r = -1 perfect correlation, where high correlate values correspond with low happiness values.
Ruut Veenhoven, World Database of Happiness, Collection of Correlational Findings, Erasmus University Rotterdam.