Reading 8: Statistical Concepts and Market Returns Flashcards

1
Q

Descriptive Statistics

A

Are used to summarize important characteristics of a large data set

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Inferential Statistics

A

Procedures used to make judgments about a larger data set based on the statistical characteristics of a smaller set (a sample)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Population

A

A set of all possible members of a stated group e.g. all stocks on NYSE

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Sample

A

A subset of the population of interest

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Types of Measurement Scales

A

Nominal
Ordinal
Interval
Ratio

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Nominal Scales

A

Data put into categories that have no particular order (range with the least amount of information)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Ordinal Scales

A

Data is put into categories that can be ordered according to some characteristics

Reveals nothing about performance differences

(Higher level of measurement than nominal)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Interval Scale

A

Temperature

Relative ranking like ordinal with differences in data values being meaningful, however ratios, such as twice as much/large are not meaningful

Measurement of zero does not mean the absence of what we are measuring

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Ratio Scale

A

Most refined level of measurement (Money)

Ratios of values (twice as much etc.) are meaningful, and zero measures the complete absence of the characteristics being measured

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Parameter

A

Numerical measure used to describe a characteristic of a population
E.g. mean or standard deviation of returns

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Sample Statistic

A

Characteristic of a Sample

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Frequency Distribution

A

Groups observations into a classes or intervals. An interval is a range of values

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Relative Frequency

A

The percentage of total observations that fall within each interval

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Cumulative Relative Frequency

A

The sum of all relative frequencies up to and including the given interval

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Histogram

A

Graphical presentation of absolute frequency distribution (Bar Chart)

Benefit: Allows us to see where most observations are concentrated

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Frequency Polygon

A

Midpoint of each interval is plotted on the horizontal axis and the absolute frequency is plotted on the vertical axis (Line Chart)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Measures of Central Tendency

A

Used to identify the center or average of a data set. Can be used to represent the expected value of a dataset

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Population Mean

A

Sum of all values in a population divided by the total number of observations in the population (only one possible mean)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Sample Mean

A

Sum of all values in a sample divided by the total number of observations in the sample (used to make inferences about the population)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Arithmetic Means (Properties)

A
  • All interval and ratio data sets have an arithmetic mean
  • All data values are considered and included
  • Only one mean
  • Sum of all deviations of each observation always equals zero
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Arithmetic Mean (Negative)

A

Outliers can have a disproportionate effect

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Arithmetic Mean (Positive)

A

Uses all information available from observations

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Weighted Mean

A

Recognizes that outliers have a disproportionate effect

Used to calculate portfolio returns (weighted average return of the individual assets in the portfolio)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Median

A

Middle number

Helps eliminate disproportionate effect of outliers

Calculate the arithmetic mean if there is an even number of observations

25
Q

Mode

A

Number that occurs most frequently in a dataset.

Unimodal, Bimodal, Trimodal

26
Q

Geometric Mean

A

Used to calculate investment returns over multiple periods

Measures compound growth rates

Always less than or equal to the arithmetic mean

27
Q

Harmonic Mean

A

Average cost of shares purchased over time

28
Q

Dollar Cost Averaging

A

Purchasing the same dollar amount of mutual fund shares each month or each week

29
Q

Modal Interval

A

The interval with the greatest frequency

30
Q

Quantile

A

A value at or below which a stated portion of the data lies

31
Q

Quartiles

A

Distribution of data into quarters

32
Q

Quntile

A

Fifths

33
Q

Decile

A

Tenths

34
Q

Percentile

A

100ths

35
Q

Quartile (Formula)

A

Ly = (n+1) * y/100
Where:
n = # of data points
y = given percentile

36
Q

Measures of Locaiton

A

Quantiles and Measures of central tendency collectively

37
Q

Dispersion

A

Variability around the central tendency (mean etc.)

38
Q

Range

A

Max - Min

39
Q

Mean Absolute Deviation (MAD)

A

Average distance between each data value and the mean. (Use absolute values e.g. ignore the mean)

40
Q

[Population] Variance

A

Average of the squared deviations from the mean

41
Q

[Population] Square Root

A

Positive square root of the population variance

NB: Standard Deviation > MAD (in general)

42
Q

Sample Variance (Difference)

A

N-1 as a denominator to ensure there is not an unbiased overestimation

43
Q

Chebyshev’s Inequality

A

1-1/k2

- the minimum percentage of the population that will lie within k standard deviations from the mean

44
Q

Coefficient Variation

A

The ratio of the standard deviation of the sample to its mean e.g. risk per unit of return

45
Q

Sharpe Ratio

A

Excess return per unit of risk
(Rp - Rf)/standard deviation

Large positive Sharpe ratios are preferred to smaller ratios (e.g. higher return)

46
Q

Limitations of the Sharpe Ratio

A
  1. Two negative ratios. Higher one doesn’t necessarily imply better returns (e.g. more risk moves it closer to zero)
  2. Asymmetric Returns e.g. investment strategies with option characteristics (standard deviation not a good measure of risk)
47
Q

Explain skewness

A

Refers to the extent to which a distribution is not symmetrical

48
Q

Positive Skew

A

Many outliers in the upper region (or right tail) so skewed right and has a longer upper right tail

49
Q

Negative Skew

A

Outliers in the lower region (left tail) so skewed left

50
Q

Where is the mean/median/mode for a positively skewed unimodal distribution?

A

Mean is greater than median, which is greater than mode

51
Q

Where is the mean/median/mode for a negatively skewed unimodal distribution?

A

Mean is less than median which is less than mode

52
Q

Kurtosis

A

Measure of peakedness relative to a normal distribution and the probability of extreme outcomes e.g. thickness of tails

53
Q

Excess Kurtosis

A

Excess Kurtosis with an absolute value greater than 1 is considered significant

Sample Kurtosis - 3

54
Q

Leptokurtic

A

More peaked

Greater probability of being close to the mean or far from the mean
(Riskier investment)

Positive Excess Kurtosis

55
Q

Platykurtic

A

Less peaked

Negative Excess Kurtosis Kurtosis

56
Q

Mesokurtic

A

Same as peakedness relative to normal

57
Q

Sample Skewness

A

Cubed (3) deviations from the mean divided by the cubed (3) standard deviation and by the number of observations

58
Q

Sample Kurtosis

A

Measured relative to the kurtosis of a normal distribution

Excess kurtosis values exceeding 1 in absolute values are considered large

59
Q

Geometric Mean / Arithmetic Mean

A

Arithmetic Mean = Forecasting single period returns in future periods

Geometric Mean = Forecasting future compound returns over multiple periods