From the statistics point of view, does an estimator may have a bias or it may be biased?

Question

Will it be correct to state that a statistical estimator may be biased, or that I must state that the above estimator may have a bias?

Is it acceptable to add the /-ed/ to the word bias in the above conditional future form?

Answer 1

Bias can be a verb as well as a noun, so it is normal to form its past participle by the addition of -ed as a suffix. May have a bias is possible, but I would guess that may be biased was more frequently used.

Answer 2

As noted in wikipedia's Biased Estimator article,

In statistics, the bias (or bias function) of an estimator is the difference between this estimator's expected value and the true value of the parameter being estimated. An estimator or decision rule with zero bias is called unbiased. Otherwise the estimator is said to be biased.

Thus, whether it is correct to state that a statistical estimator may be biased depends on the facts; ie, depends on whether the estimator may be biased, or can be shown to be unbiased.