1[2 {"id":"C1","text":"The memo's conclusion that the slope of y on x is statistically significant at the 5% level is not supported once HAC (Newey-West, 9 lags) standard errors are used: t = 1.56, p = 0.12, and the 95% CI contains 0.","results_keys":["memo_claim_supported","t_hac","p_hac","beta_ci_low","beta_ci_high","se_hac","hac_lags"],"status":"unsupported","caveat":"This is the memo's claim; status 'unsupported' is my verdict on it. Newey-West tests tend to over-reject with persistent data, which would only strengthen this verdict."},3 {"id":"C2","text":"The memo's arithmetic is reproduced: intercept 2.0925, slope 0.1017, iid SE 0.0448, t 2.27, p 0.0238 on 400 observations.","results_keys":["alpha_hat","beta_hat","se_iid","baseline_t_iid","baseline_p_iid","n_analysed"],"status":"supported","caveat":"Matches the memo to rounding; the problem is the iid SE assumption, not the computation."},4 {"id":"C3","text":"OLS residuals are strongly serially correlated (first-order autocorrelation 0.61), and the HAC SE is about 1.46 times the iid SE.","results_keys":["rho_resid","se_ratio_hac_over_iid","se_iid","se_hac"],"status":"supported","caveat":"The residual autocorrelation is estimated from OLS residuals, so it is slightly biased downward."},5 {"id":"C4","text":"The not-significant verdict holds for every HAC bandwidth from 5 to 24 lags (p between 0.115 and 0.125).","results_keys":["hac_sensitivity_by_lag","nw1994_rule_lags","andrews_bandwidth_raw"],"status":"supported","caveat":"Only Bartlett-kernel Newey-West estimators were examined; fixed-b and GLS alternatives were not computed."}6]7