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What is meant by consistent estimator?
In statistics, a consistent estimator or asymptotically consistent estimator is an estimator—a rule for computing estimates of a parameter θ0—having the property that as the number of data points used increases indefinitely, the resulting sequence of estimates converges in probability to θ0.
Is consistent estimator unbiased?
An unbiased estimator is said to be consistent if the difference between the estimator and the target popula- tion parameter becomes smaller as we increase the sample size. Formally, an unbiased estimator ˆµ for parameter µ is said to be consistent if V (ˆµ) approaches zero as n → ∞.
What is the property of a consistent estimator?
In statistics, a consistent estimator or asymptotically consistent estimator is an estimator—a rule for computing estimates of a parameter θ 0—having the property that as the number of data points used increases indefinitely, the resulting sequence of estimates converges in probability to θ 0.
Which is the consistent sequence of estimators for θ0?
{ T1, T2, T3.} is a sequence of estimators for parameter θ0, the true value of which is 4. This sequence is consistent: the estimators are getting more and more concentrated near the true value θ0; at the same time, these estimators are biased.
How to estimate μ based on the first n observations?
To estimate μ based on the first n observations, one can use the sample mean: Tn = ( X1 + + Xn )/ n. This defines a sequence of estimators, indexed by the sample size n . From the properties of the normal distribution, we know the sampling distribution of this statistic: Tn is itself normally distributed, with mean μ and variance σ2 / n.
When is a consistency estimator called weak consistency?
Consistency as defined here is sometimes referred to as weak consistency. When we replace convergence in probability with almost sure convergence, then the estimator is said to be strongly consistent.