1[2 {"id":"C1","text":"In 2023 (n=197 countries/economies), life expectancy rises with ln(GDP per capita): OLS slope 5.27 years per log-point, HC3 95% CI [4.85, 5.68], entirely above zero.","results_keys":["analysis_year","n_analysed","effect_estimate","effect_se","effect_ci_low","effect_ci_high","conclusion"],"status":"supported","caveat":"Descriptive association, not causal; 20 economies excluded for missing GDP, non-randomly."},3 {"id":"C2","text":"The relationship is strong: Pearson r = 0.86, R² = 0.74.","results_keys":["pearson_r","r_squared"],"status":"supported","caveat":"In-sample fit; equal country weights."},4 {"id":"C3","text":"Log income roughly halves prediction error relative to the mean-only baseline (RMSE 7.08 -> 3.59 years).","results_keys":["baseline_metric","model_metric"],"status":"supported","caveat":"In-sample RMSE; no cross-validation performed."},5 {"id":"C4","text":"The analysis year is 2023, the latest year with >=150 complete countries; 20 countries/economies were excluded for missing GDP per capita.","results_keys":["analysis_year","n_excluded_missing","n_analysed"],"status":"supported","caveat":"All excluded cases lack GDP pc PPP; LE was complete."}6]7