1[2 {"id":"C1","text":"The OLS Okun coefficient for 1960Q1-2019Q4 (240 quarters) is about -0.256 pp of unemployment per 1% 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":"Reduced-form linear projection, full-sample average; not causal."},3 {"id":"C2","text":"The Newey-West (Bartlett, 4 lags) standard error is 0.0358, about 1.8 times the conventional SE of 0.0200, reflecting positive residual autocorrelation.","results_keys":["se_hac","se_iid","hac_lags","resid_acf_lags1to4"],"status":"supported","caveat":"Bandwidth from the Newey-West (1994) rule of thumb, not an automatic selector."},4 {"id":"C3","text":"The 95% HAC confidence interval for beta is [-0.326, -0.186]; the Okun coefficient is negative and significantly different from zero at the 5% level (HAC t = -7.14).","results_keys":["beta_ci_low","beta_ci_high","okun_negative_5pct","t_stat_hac","p_value_hac"],"status":"supported","caveat":"Asymptotic normal critical value; fixed-b corrections not computed."},5 {"id":"C4","text":"The significance conclusion is robust to HAC bandwidths from 0 to 12 lags (SE between 0.029 and 0.037).","results_keys":["se_hac_by_lag","beta_hat"],"status":"supported","caveat":"Only lags 0,1,2,4,6,8,12 evaluated."},6 {"id":"C5","text":"Mean quarterly real GDP growth over the sample is 0.754%; the only data issue (missing UNRATE for 2025-10) lies outside the analysis window.","results_keys":["mean_growth","data_issues","n_input_rows"],"status":"supported","caveat":"Current-vintage data, not real-time."}7]8