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Project OneCarpoll

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Carpoll

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Excel Convert categorical data into dummy

variables Type of vehicle: family, sporty, work Sort type

Select some of family observations Expand selection in dialog box

Code family as one, sporty and work as zero

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Vehicle Type Family

Yes: One, 155 No: zero, 148 Total: 303

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Plot of Family Type (Zero/One) Vs. Age

y = 0.0196x - 0.0891

R2 = 0.0546

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0 10 20 30 40 50 60 70

Age

Pro

bab

ilit

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Approximation to Cumulative Distribution Function Sigmoid

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Sort Gender and Code zero/one Male: one; Female: zero

Select some observations in sex, expand selection, sort

Ditto for marital status Married: one Single: zero

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Cross-Classification of Type with GenderFamily Sporty &

WorkTotal

Female 76 62 138

Male 79 86 165

Total 155 148 303

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#-Way classification in one step

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Family: YesMarried Single Total

Female 58 18 76

Male 61 18 79

Total 119 36 155

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Cut and Paste Fambern, age, gender, marital into EViews

File Menu New

workfile

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Workfile Dialog Box

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Generate x = 1

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Estimate Linear Probability Model

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Age and marital are significant,And have a positive effect on The probability of choosing aFamily car. Gender barely addsto the explanation and is negative

Given age and gender, being married increases the

Probability of favoring a family car by 0.23

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Married and Female

Single and Male

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Married and Female

Single and Male

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This probability model does a better job of explaining thoseWho favor a family car comparedTo those who don’t

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Logit Fit

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Married women

Single men

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Linear Probability Model Car Size Car size: Small, medium, large Varies with age, gender, and marital status

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Sort by Size and then by Age

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Contingency Table Analysis: ObservedSmall Medium Large Margin

18-29 70 59 15 149

30-39 59 58 21 138

40- 8 7 6 21

Margin 137 124 42 303

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Contingency Table Analysis: Small Medium Large Margin

18-29 149

30-39 138

40- 21

Margin 137 124 42 303

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Contingency Table Analysis: ExpectedSmall Medium Large Margin

18-29 67.4 61.0 20.7 149

30-39 62.4 56.5 19.1 138

40- 9.5 8.6 2.9 21

Margin 137 124 42 303

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Contingency Table Analysis: [Observed – Expected]2

Small Medium Large

18-29 6.76 4.0 32.49

30-39 11.56 2.25 3.61

40- 2.25 2.56 9.61

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0.00

0.05

0.10

0.15

0 5 10 15

CHIR

DE

NS

9.5

5%

2 =75.09

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Contingency Table Analysis: Small Medium Large

18-29 Fewer than exp

30-39 Fewer than exp

40- More than exp

Margin

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Summary

People in their 20’s prefer smaller cars People in their forties or older prefer large

cars

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Country Vs. Size Country: American, European, Japanese Size: small, medium, large

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Contingency Table Analysis: Observed Small Medium Large Margin

American 26 19 92 137

European 53 17 54 124

Japanese 36 4 2 42

Margin 115 40 148 303

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Contingency Table Analysis: Small Medium Large Margin

American 137

European 124

Japanese 42

Margin 115 40 148 303

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Contingency Table Analysis: Expected Small Medium Large Margin

American 52.0 18.1 66.9 137

European 47.1 16.4 60.6 124

Japanese 15.9 5.5 20.5 42

Margin 115 40 148 303

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Contingency Table Analysis: [Observed – Expected]2

Small Medium Large

American 676 0.81 630

European 34.8 0.36 43.6

Japanese 404 2.25 342

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Contingency Table Analysis: Small Medium Large

American fewer than exp

more

European

Japanese more fewer

Margin

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Summary Preference for large American cars and for

small Japanese cars.