1[2 {"id":"C1","text":"The OLS Okun coefficient over 1960Q1-2019Q4 (n=240) is about -0.256 pp of unemployment per percent of quarterly real GDP growth, with intercept 0.184 and R^2 0.408.","results_keys":["beta_hat","alpha_hat","r_squared","n_analysed","first_quarter","last_quarter"],"status":"supported","caveat":"Current-vintage data; descriptive linear projection, not causal."},3 {"id":"C2","text":"The Newey-West (Bartlett, 4 lags) standard error is 0.0358, giving a 95% CI of [-0.326, -0.186]; the Okun coefficient is negative and significant at the 5% level.","results_keys":["se_hac","hac_lags","beta_ci_low","beta_ci_high","okun_negative_5pct","t_stat_hac","p_value_hac"],"status":"supported","caveat":"Asymptotic normal inference, rule-of-thumb bandwidth, no small-sample correction."},4 {"id":"C3","text":"Residuals are positively autocorrelated (lag-1 0.39) and the HAC SE is about 1.8 times the naive iid SE (0.0200), so iid inference overstates precision.","results_keys":["se_iid","se_hac","resid_lag1_autocorr","baseline_beta_ci_low_iid","baseline_beta_ci_high_iid"],"status":"supported","caveat":""},5 {"id":"C4","text":"The significance conclusion is robust to the HAC bandwidth (lags 0-12 give SEs 0.029-0.037).","results_keys":["se_hac_by_lags"],"status":"supported","caveat":"Only a finite set of bandwidths tried."},6 {"id":"C5","text":"Mean quarterly real GDP growth in the sample is 0.754%; the implied unemployment-stabilising growth rate is about 0.72% per quarter.","results_keys":["mean_growth","alpha_hat","beta_hat"],"status":"supported","caveat":"The 0.72% figure is a derived ratio -alpha_hat/beta_hat with no reported uncertainty."}7]8