Correlational finding on Happiness and subject: Current age (in years)

StudyMujcic & Oswald (2016): study AU 2007
TitleEvolution of Well-Being and Happiness After Increases in Consumption of Fruit and Vegetables.
SourceAmerican Journal of Public Health, 2016, Vol 106, 1504 - 1510
URLhttps://www.ncbi.nlm.nih.gov/pubmed/27400354
DOIdoi: 10.2105/AJPH.2016.303260.
Public18+ aged general public, Australia, followed 3 years 2007-2009
SampleProbability multi-stage cluster sample
Non-Response
Respondents N =12385

Correlate
Author's labelAge
Page in Source table 1
Our classificationCurrent age (in years)
Operationalization
a: age in years
b: age squared
Observed distributionRange: 15- 9;, M: 45,16; SD: 17,89

Observed Relation with Happiness
Happiness
Measure
StatisticsElaboration/Remarks
O-SLW-u-sq-n-11-db-fix=-.01 p < .758
Age in years:: CI95 [-.06, +.04]
O-SLW-u-sq-n-11-db-fix=+.01 p < .720
Age squared: CI95[.06, +.04] controled for:

b-fix's controled for:
- CHANGE daily consumption of fruits and 
vegetables
- CURRENT
  - socio-demographics
    - income
    - education
    - marital status
    - employment
  - long-term health condition
  - number of children

Unaffected by additional control for:
- health behavior
- BMI


Appendix 1: Happiness measures used
CodeFull Text
O-SLW-u-sq-n-11-dSelfreport on single question:

All things considered, how satisfied are you with your life?
Again, pick a number between 0 and 10 to indicate how satisfied you are.
0 totally dissatisfied
1
2
3
4
5
6
7
8
9
10 totally satisfied


Appendix 2: Statistics used
SymbolExplanation
b-fixREGRESSION COEFICIENT in fixed effects analysis
Type: test statistic
WDH symbol: b-fix
Primary correlate level: metric
Secondary correlate level: nonmetric
Happiness level: metric
Theoretical range: unlimited
Meaning:
Variant of usual (non-standardized) regression coefficient (b), which controls for the secondary variables, by focusing on differences from a fixed level, such as the mean in a category. Aims to reduce the residual variance and to improve the precision of the regression coefficient.

References:
Wikipedia: http://en.wikipedia.org/wiki/Fixed_effects_model
Non-technical text: http://www.jblumenstock.com/files/courses/econ174/FEModels.pdf
Source:
Ruut Veenhoven, World Database of Happiness, Collection of Correlational Findings, Erasmus University Rotterdam.
https://worlddatabaseofhappiness.eur.nl