Separating the active and the aging in the Active Aging Index

UNECE Second international seminar on the Active Ageing Index, Bilbao. 28 September 2018
José Antonio Ortega

Workshop on methodological papers Usal

The problem

  • The AAI incorporates 22 dimensions of active aging into a single indicator that is useful for policy design and analysis.
  • A limitation of the AAI: many of the indicators are based on prevalence of a certain behaviour in a particular subpopulation (eg: 55+) with no adjustment for age composition.

This can be a problem:

Indices cannot be readily compared over time (or over sex), since change depends both on changes in population composition and the underlying active aging dimension.

Possible solutions

Demographic approach

  • Age-specific indicators: Like some AAI dimensions (labor force, 1)
  • Synthetic indicators: Like remanining life expectancy at age 55 (4.1)
  • Direct standardization: Apply age-specific proportions or rates to a standard population.

Best solution

But requiring age-specific measurement.

REGRESSION APPROACH (ours)

  • Hypothesis: Rates and proportions depend on age.
  • Consequence: Aggregate indices depend on age composition (aging)
  • Regression on aging indicators estimates the effect of age composition on the indicator.
  • Based on such estimates, an adjusted AAI indicator can be obtained referring to a standard aging level.

It only requires aggregate data

Interpretation different from demographic approach.

Specific example: Physical exercise in Spain 55+

plot of chunk unnamed-chunk-1

  • Mean weekly exercise depends on age and sex.
  • Since women 55+ are older than men 55+ due to lower mortality, age-composition exaggerates the differences between men and women in the aggregate index.
  • Age-profile provides richer information.
  • Demographic methods would work: Same standard.
  • Regression approach:
    • Complex profile: For males increasing activity until age 70, more time available to pensioners
    • Several aging indicators needed.

Aging-effects in regression

\( I_{it} = f(Z_i,Aging_{it},X_{it}) \)

  • \( I_{it} \) - Indicator for time \( t \) and region-sex \( i \)
  • \( Z_i \) - Variables that do not change over time.

    • Controlled for using fixed-effects
  • \( \text{Aging}_{it} \) - Vector of aging related variables

  • \( X_{it} \) - Other non-aging related variables changing over time.

Different from demographic approach.

  • Mechanistic effect of age-composition due to underlying rates depending on age \( I_{ita} \)

Other reasons why aging might matter:

  • Examples:

    • Direct effects of aging: E.g: competition in labor markets, political impact through elections, …
    • Social adaptation to aging

Our regression approach

Separate fixed-effect regressions for each AAI indicator (\( 22 \times 3 \)) for the period 2010-2018 (5 time periods, EU-28 countries)

\[ I_{it}=\alpha + \text{Aging}_{it}' \beta + \mu_{i}+ \varepsilon_{it} \]

  • Fixed-effects \( \mu_i \) control for unchanging country characteristics (eg: age-friendly culture)
  • \( \text{Aging}_{it} \) include proportions 55-64, 65+, and average age of population 65+ (from Eurostat)
  • \( \varepsilon_{it} \) error term
  • The aging vector adapts to complex situations such as different effects for different age-groups.
  • Aging coefficients will capture both mechanistic effects (for indicators that do not control for age), and direct and indirect effects of aging (operating through other time-varying determinants that are correlated with trends in aging indicators)

Adjusted AAI Index

For each indicator and sex, an adjusted indicator is obtained as:

\[ I_{its}'=I_{its}- (x_{its}-x^0_{is})'\hat\beta \]

  • The adjusted indicator corresponds to what would have been the indicators if aging corresponded to sex-specific average-values in the EU in 2015.
  • Adjustment is carried out only for those indicators where aging coefficients are significantly different from zero (p-value 0.05, robust test statistics)
  • The adjusted indices can be interpreted as representing the active part of the AAI.
  • Contribution of aging is obtained as the ratio \( \frac{I_{it}'}{I_{it}} \).
  • Aggregate indicators can be obtained using standard AAI definitions.

Aging effects in different AAI indicators

Test statistics and p-values on null hypothesis of no aging effect for all indicators in the Active Aging Index by sex

  • For most indicators, but not for every indicator. the null of no effect of aging variables can be rejected at 5% significance level.
  • Indicators where the null of no effect is not rejected include:
    • 2.1 (Voluntary activities)
    • 3.1 (Physical exercise) for women and both sexes, 3.2 (Access to health services), 3.8 (Lifelong learning)
    • 4.5 (Social connectedness)
    • Indicators already standardized by age (4.2, share of healthy life expectancy at age 55)
    • Two of the four employment rates: 1.3, 65-69, 1.4, 70-74.

Regression coefficients for employment indicators

Regression coefficients of selected aging indicators for employment rate indicators (both sexes)

  • Employment indicators are age-specific: No need for demographic adjustment.
  • Those for younger workers, 55-59 and 60-64 are partly explained by aging variables.
  • Economic logic:
    • Increasing proportions of the population in the 55-64 and 65+ are connected with higher participation (less proportion in younger ages)
    • Smaller effects at older ages: Labor market institutions more influential than aging.
    • Coefficients tend to be positive: Suggests succesful adaptation to aging of labor markets.

Coefficients positive for most indicators

Individual coefficients of aging variables statistically significant at the 0.05 level by AAI indicator and sex

  • All statistically significative coefficients are positive
  • Contrary to expected indicators do not get worse as populations age.
  • Whenever they are connected to aging, as societies have aged, active aging indicators have improved.
  • Explanations:
    • Succesful adaptation.
    • Indirect effects connected to third variables associated with aging indicators.
    • Cohort survival, health and education levels improving?

4.1, remaining life expectancy at age 55

Regression coefficients of selected aging indicators on indicator 4.1, remaining life expectancy at age 55

  • Positive coefficients for aging variables
  • No need for demographic adjustment: synthetic indicator
  • This is a case of joint determination:
    • More survival leads to higher proportions of elderly and higher mean age.
    • More survival means higher life expectancy at ages 65.
  • In this sense, more aging is a success story in itself.

Adjusted indicators: Aging factors

plot of chunk unnamed-chunk-2

Country-specific aging corrections at the dimension level.

  • Aging factors generally increase over time in a relatively homogeneous manner across countries: active aging indicators get higher as countries age
  • Aging corrections are more important for females than for males.
  • Aging corrections are particularly important for dimension 1 (employment) and 2 (participation in society).

Separating the Active (AAI') and the aging (Aging factor) in the 2018 AAI (Both sexes)

Separating the active (AAI') and aging (Aging factor) in the 2018 AAI for both sexes

Aging factors for each dimension in the 2018 AAI (both sexes)

Aging factors for each dimension in the 2018 AAI for both sexes

Conclusions

  • AAI framework and our understanding of active ageing can improve by incorporating age dependence.
  • Demographic adjustment provides comparable indicators among countries and sexes.
  • Regression adjustment is not equivalent to demographic adjustment.
  • Contrary to expectations, active aging indicators have generally improved as the aging process proceeded
  • Possible explanation: Improved cohort survival and personal characteristics (wealth, health, education) have affected both the aging process and active aging.
  • No matter the explanation, a positive finding is that European societies have so far been able to cope with aging so that the increased presence of older people in the population has not meant lower levels of active aging. Rather the reverse is true: there are more aged people in societies because generations arriving at older ages are more prepared to live an active life at older ages, and/or societies are sucessfully adapting to the needs of older people.