TABLE 3

Effect of sequence length on sampling properties of MLEs

θ (= ρ)Mean (Embedded Image )SD (Embedded Image )θ in C.I.Embedded Image Embedded Image ρ in C.I.Embedded Image Embedded Image ρ/θ in C.I
10.990.54960.550.231000.670.2499
21.000.43950.650.41980.710.3597
31.000.311000.80.50940.80.5092
  • Shown are estimated means and standard deviations of the maximum-likelihood estimates of θ; estimated median of maximum-likelihood estimates of ρ and ρ/θ; g, the proportion of times that the MLE is within a factor of 2 of the truth; and coverage properties of an ~95% confidence interval (calculated using a chi-square approximation to the likelihood ratio statistic). Results are based on 100 samples (each of size 50) for each of the three sequence lengths.