Asymptotics Primer - University of Washington · Asymptotics Primer Econ 583 Econometric Theory I...

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1 Asymptotics Primer Econ 583 Econometric Theory I Fall 2008 Consistency of Sample Mean from iid N(0,1) Data Sample Size, T Sample Mean 0 200 400 600 800 1000 0.0 0.2 0.4 0.6

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Page 1: Asymptotics Primer - University of Washington · Asymptotics Primer Econ 583 Econometric Theory I Fall 2008 Consistency of Sample Mean from iid N(0,1) Data Sample Size, T Sample Mean

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Asymptotics Primer

Econ 583Econometric Theory I

Fall 2008

Consistency of Sample Mean from iid N(0,1) Data

Sample Size, T

Sam

ple

Mea

n

0 200 400 600 800 1000

0.0

0.2

0.4

0.6

Page 2: Asymptotics Primer - University of Washington · Asymptotics Primer Econ 583 Econometric Theory I Fall 2008 Consistency of Sample Mean from iid N(0,1) Data Sample Size, T Sample Mean

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Consistency of Sample Mean from iid U(-1,1) Data

Sample Size, T

Sam

ple

Mea

n

0 200 400 600 800 1000

0.0

0.2

0.4

0.6

Consistency of Sample Mean from iid Chi-Square 1 Data

Sample Size, T

Sam

ple

Mea

n

0 200 400 600 800 1000

0.0

0.2

0.4

0.6

0.8

1.0

1.2

2[ (1)] 1E χ =

Page 3: Asymptotics Primer - University of Washington · Asymptotics Primer Econ 583 Econometric Theory I Fall 2008 Consistency of Sample Mean from iid N(0,1) Data Sample Size, T Sample Mean

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Sample Mean from iid Student's t with 1 df

Sample Size, T

Sam

ple

Mea

n

0 200 400 600 800 1000

-20

24

68 Student’s t with 1 df = Cauchy

Expected value of Cauchy rv does not exist because tails are too thick

N(0,1) Data

Sample Size, T

Sam

ple

Mea

n

0 200 400 600 800 1000

-3-1

01

2

U(-1,1) Data

Sample Size, T

Sam

ple

Mea

n

0 200 400 600 800 1000

-1.0

0.0

0.5

1.0

Chi-Square 1 Data

Sample Size, T

Sam

ple

Mea

n

0 200 400 600 800 1000

01

23

45

6

Cauchy Data

Sample Size, T

Sam

ple

Mea

n

0 200 400 600 800 1000

-600

-200

0

100 Simulated Sequences of Yn

Page 4: Asymptotics Primer - University of Washington · Asymptotics Primer Econ 583 Econometric Theory I Fall 2008 Consistency of Sample Mean from iid N(0,1) Data Sample Size, T Sample Mean

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T = 25

mu.hat

dens

ity

-1.0 -0.5 0.0 0.5 1.0

0.0

0.5

1.0

1.5

2.0

T = 50

mu.hat

dens

ity

-1.0 -0.5 0.0 0.5 1.0

0.0

0.5

1.0

1.5

2.0

2.5

T = 100

mu.hat

dens

ity

-1.0 -0.5 0.0 0.5 1.0

01

23

4

T = 1000

mu.hat

dens

ity

-1.0 -0.5 0.0 0.5 1.0

02

46

810

12

Distribution of Sample Mean for iid N(0,1) data

( )SD XT

σ=

-2 0 2

0.0

0.1

0.2

0.3

0.4

T=10

z.10

-4 -2 0 2

0.0

0.1

0.2

0.3

T=25

z.25

-3 -2 -1 0 1 2 3

0.0

0.1

0.2

0.3

0.4

T=50

z.50

-3 -2 -1 0 1 2 3

0.0

0.1

0.2

0.3

0.4

T=100

z.100

for ~ (0,1)iXT X iid Nμσ−⎛ ⎞

⎜ ⎟⎝ ⎠

Page 5: Asymptotics Primer - University of Washington · Asymptotics Primer Econ 583 Econometric Theory I Fall 2008 Consistency of Sample Mean from iid N(0,1) Data Sample Size, T Sample Mean

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2for ~ (1)iXT X iidμ χσ−⎛ ⎞

⎜ ⎟⎝ ⎠

-2 0 2 4 6

0.0

0.1

0.2

0.3

0.4

T=10

z.10

-2 -1 0 1 2 3

0.0

0.1

0.2

0.3

0.4

T=25

z.25

-2 0 2 4

0.0

0.1

0.2

0.3

0.4

T=50

z.50

-2 0 2

0.0

0.1

0.2

0.3

0.4

T=100

z.100