Correlational finding on Happiness and subject: Healthy eating

StudyGschwandtner et al. (2015): study GB 2012
TitleOn the Relationship between Lifestyle and Happiness in the UK.
SourcePaper for 89th Annual Conference of AES, 2015, 1 - 33, Warwick, England
Public16+ aged, general public UK, 2012
SampleProbability multistage stratified area sample
Respondents N =31946

Author's labelAverage daily portions of fruits and vegetables
Page in Source table 1 + 2
Our classificationHealthy eating
Average daily portions of fruit and vegetables
1: none (reference)
2: 1-2
3: 2-3
4: 3-4
5: 4-5
Observed distributionMales: M = 3,86; SD = 3,06. Females: M = 3,02; SD = 2,74

Observed Relation with Happiness
O-SLW-u-sq-n-7-eb=+ s
1-2 portions per day (vs none)
- males:  +.09 (05)
- females + 15 (01)
O-SLW-u-sq-n-7-eb=+ s
2-3 portions per day (vs none)
- males:  +.16 (01)
- females + 14 (01)
O-SLW-u-sq-n-7-eb=+ s
3-4 portions per day (vs none)
- males:  +.19 (01)
- females + 27 (01)
O-SLW-u-sq-n-7-eb=+ s
4-5 portions per day (vs none)
- males:  +.20 (01)
- females + 30 (01)

b's controled for:
- socio-economic backgroud (parents education)
- age 
- education
- marital status
- age of youngest child
- ethnicity
- employment status
- region
- health behavior
  - days walk
  - sporting
Stronger effects in instrumental variable analysis 
in which the net effect of sporting on happiness 
is controled. This suggest a causal effect of 
fruit/vegagetable consumption on happiness

Appendix 1: Happiness measures used
CodeFull Text
O-SLW-u-sq-n-7-eSelfreport on single question:

How dissatisfied or satisfied are you with your life as a whole?
1 not satisfied at all
7 completely satisfied

Appendix 2: Statistics used
Type: test statistic
Measurement level: Correlate: metric, Happiness: metric
Theoretical range: unlimited

b > 0 A higher correlate level corresponds with a higher happiness rating on average.
B < 0 A higher correlate level corresponds with a lower happiness rating on average.
B = 0 Not any correlation with the relevant correlate.
b-ivREGRESSION COEFFICIENT in regression ananlysis with instrumental variable as one or more explanatory variables
Type: test statistic.
Correlate level: metric, Happiness level: metric
Theoretical range: unlimited

The instrument must be correlated with the endogenous explanatory variables, conditionally on the other covariates. If this correlation is strong, then the instrument is said to have a strong first stage. A weak correlation may provide misleading inferences about parameter estimates and standard errors.
The instrument cannot be correlated with the error term in the explanatory equation, conditionally on the other covariates. In other words, the instrument cannot suffer from the same problem as the original predicting variable. If this condition is met, then the instrument is said to satisfy the exclusion restriction.

See Mardia Kent & Bibby (1979): Multivariate Analysis
Ruut Veenhoven, World Database of Happiness, Collection of Correlational Findings, Erasmus University Rotterdam.