Sampling & Estimation Flashcards
A method of selecting a sample in such a way that each item or person in the population being studied has the same probability of being included in the sample
Simple random sampling
The distribution of all values that a sample statistic can take on when computed from samples of identical size randomly drawn from the same population
Sampling distribution
The difference between a sample statistic and its corresponding population parameter
Sampling error
Randomly selecting samples proportionally from subgroups that are formed based on one or more distinguishing characteristics
Stratified random sampling
Data consisting of observations taken at specific and equally spaced points in time
Time-series data
Data consists of observations taken at a single point in time
Cross-sectional data
Standard error formula
= σ or s / SQRT(n)
Sign of estimation error is random
Unbiased
Lower sampling error than any other unbiased estimator
Efficiency
Variance of the sampling error decreases with larger sample size
Consistency
Distribution defined by degrees of freedom
t-statistic
Bias that involves significant relationships that have occurred by chance
Data mining bias
Bias where selection is nonrandom
Sample selection bias
Bias where the test is based at a point in time on data not available at that time
Look-ahead bias
Bias that uses only surviving mutual funds, hedge funds, etc.
Survivorship bias
