2-footprint-test-and-regression-model-how-to-deal

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Co-finanziato

Dal Programma LLP dell’Unione Europea

F o o t p r i n t test and

Regression model : how to deal with data?

L’autore è il solo responsabile di questa comunicazione. L’Unione europea declina ogni responsabilità sull’uso che potrà essere fatto delle informazioni in essa contenute.

F o o t p r i n t

The ecological footprint is a measure of human demand on the Earth's ecosystems. It is a standardized measure of demand for natural capital that may be contrasted with the planet's ecological capacity to regenerate

Ecological footprint F is calculated by this equation:

E i

= ecological footprint coming from the waste q i

C i

= product i-th

= (hectare/kg) reciprocal of the average productivity per hectare produced the i-th.

The ecological footprint per capita f is calculated by dividing for the population N residing in the region considered:

Studies carried out on a global scale and in some countries shows that the global footprint is larger than the capacity bioproductive world. According to Mathis

Wackernagel, in 1961 humanity used 70% of the overall capacity of the biosphere, but in 1999 had increased to 120%.

Ecological footprint in the world

Evidence through observation

To find out whether and how our actions and lifestyle affect our environment

We selected an appropriate

Ecological footprint calculation quiz - as a methods for collecting relevant information related to our environment and lifestyle

We adopted strategies for planning, organizing and most efficiently manage a Footprint quiz

- Pointing out criteria for making right questions in order to ensure accuracy, significance, and fairness about collected data

- Administering the “ Footprint Test” to a quantitative significant sample of people of Pisa area

Footprint TEST

• I travel mostly by 1- car ( average user )

2- car ( heavy user )

3- car (light user )

4- bus/train

5- walking/cycling

6- motorbike

• usually holiday 1- close to home

2- a short flight away

3- a long flight away

• I live in a 1 – large house

2 – medium-sized house

3 – small house

4 – flat/apartment

5 – zero emission development

• that I share with 1 – no other person

2 – one other person

3 – two other person

4 – three other person

5 – four other person

6 – five other person

7 – six other person

8 – more than six others

• My heating/cooling bills are relatively

1 – normal

2 – high

3 – low

• I buy my electricity from

1 – non-renewable sources

2 – renewable sources

• I tend 1 – not to conserve energy

2 – to conserve energy

• I am 1 – a regular meat-eater

2 – an occasional meat-eater

3 – a heavy meat-eater

4 – a vegetarian

5 – a vegan

• usually eat

1 – a mix of fresh and convenience foods

2 – mostly fresh, locally grown produce

3 – mostly convenience foods

• I produce 1 – an average

2 – a below average

3 – an above average

4 – half the average amount of domestic waste

• most of which is 1 – not recycled

2 – recycled

Aim of our research: to study the impact of specific characteristics of the respondents about their ecological footprint.

How we made it: For data processing we used methods provided by a branch of statistics known as econometrics.

Econometrics may be defined as a branch of statistics that deals with the analysis of economic phenomena, or alternatively, can be considered a sector of the economy devoted to the empirical verification of theoretical models formulated in scope.

In our survey,

- we applied several statistic methods and techniques to collect data

- we focused on the

Regression Model for managing and analyzing quantitative data

A Math /Stats Model

1.

Often Describe Relationship between

Variables

2.

Types

-

Deterministic Models (no randomness)

-

Probabilistic Models (with randomness)

EPI 809/Spring 2008 26

1.

2.

Hypothesize Exact Relationships

Suitable When Prediction Error is

Negligible

EPI 809/Spring 2008 27

1.

Hypothesize 2 Components

Deterministic

Random Error

EPI 809/Spring 2008 28

Probabilistic

Models

Regression

Models

Correlation

Models

Other

Models

EPI 809/Spring 2008 29

Relationship between one dependent variable and explanatory variable(s)

Use equation to set up relationship

Numerical Dependent (Response) Variable

1 or More Numerical or Categorical

Independent (Explanatory) Variables

Used Mainly for Prediction &

Estimation

EPI 809/Spring 2008 30

1. Hypothesize Deterministic

Component

Estimate Unknown Parameters

2. Evaluate the fitted Model

3. Use Model for Prediction &

Estimation

EPI 809/Spring 2008 31

1. Define the dependent variable and independent variable

2. Hypothesize Nature of

Relationship

• Expected Effects (i.e., Coefficients’

Signs)

EPI 809/Spring 2008 32

1. Relationship Between Variables

Is a Linear Function

Population

Y-Intercept

Population

Slope

Y i

 

0

 

1

X i

  i

Dependent

(Response)

Variable

(e.g., CD+ c.)

Random

Error

Independent

(Explanatory) Variable

(e.g., Years s. serocon.)

Y

Y i

 

0

 

1

X i

  i

Observed value

i = Random error

E

  

0

1

X i

Observed value

EPI 809/Spring 2008 34

Population

Y i

Unknown

Relationship

 

0

 

1

X i

 i

 

EPI 809/Spring 2008

Random Sample

Y i

  

0

  

1

X i

   i

35

1. Theory of Field (e.g.,

Epidemiology)

2. Mathematical Theory

3. Previous Research

4. ‘Common Sense’

EPI 809/Spring 2008 36

Y

Y i

  

0

  

1

X i

   i

 ^

i = Random error

Y

 i

  

0

   X

1

X i

Unsampled observation

Observed value

EPI 809/Spring 2008 37

Our data: the application of this methodology of statistical analysis requires the identification of a dependent variable and multiple independent variables. The independent variables will be the ones through which will be explained the variance of the dependent variable. These are the variables identified for this project:

• dependent variable:

Through a test on footprint, administered to a large and significant sample , we will obtain a value that expresses the footprint of a subject;

• independent variables:

- age

- usually

- Number of people in household

- distance home-school/work

(categorical variable: 1 =

5km, 10km = 2, 3 = 15km)

sensitization (categorical variable: 1

= "I never discussed the issue of energy and pollution in school or personally," 2 = "I did a course of primary awareness on energy and pollution", 3 = "I have dealt with in depth and more than once the subject of energy and pollution") where for a categorical variable we mean a variable measured at different levels (categories).

Estimation model: starting from the estimation equation:

Y = a + bX + c Z + e

(where e is the error of our estimate a,b,c constant, and together account for the variation in Y not explained by our dependent variables) we obtain the following equation that represents our model to estimate

Footprint

a + b age + c sort + d sensation

+…. + e

From this equation we will get different values for the coefficients b, c, d ... that will allow us to see how the footprint vary with age, gender, and so on.

Specifically:

- the absolute value of the coefficient indicates the strength of the effect of the independent on the dependent variable.

What next?

Next year the above model will be estimated using a specific statistics program : Stata

.

The following slides report our collected data from Footprint quizzes

M

M

M

M

M

M

M

F

F

F

F

F

Sesso Età Dist. Casa scuola

M 14 6

24

51

47

65

56

5

10

15

10

3

16

17

17

16

16

13

16

5

10

5

5

15

1,5

10

2

1

2

2

1

1

1

1

3

2

2

3

Sensibil ità

2

8,7

6,9

6,5

9,3

7,9

6

6,8

CO2 (t) Ettari globali

7,1 4,4

8,8

10,3

8,9

8,2

7,5

4,8

6,2

5,2

4,4

4,4

4,4

4,1

3,1

5,3

3,8

4,4

4,3 pianeti

2,7

2,7

2,3

2,7

2,6

2.7

3

3,8

3,2

2,7

2,5

1,9

3,2

M

F

F

F

M

F

M

F

M

M

M

M

F m

18

42

20

19

19

16

16

9

18

17

18

19

54

16

2

1

2

1

2

1

1

2

2

1

1

2

2

2

10

5

13

12

5

10

20

3

3,6

7

20

5

1,5

15

9,9

6,3

7,1

7,5

6,3

6,3

6,2

9,3

7,6

6,4

5,1

4

8,2 4,6

11,3 5,9

9,5 4,6

10,4 6,1

4,1

3,3

5

5,4

3,7

4,3

4,5

3,3

3,3

2,3

2,7

2,8

2

3,1

2,4

2,8

3,6

2,8

3,7

2,5

2

3,1

M

M

M

F

F

F

F

F

M

F

M

F

F

M

18

1

17

16

17

17

14

18

17

14

14

14

15

15

5

0,3

10

30

20

0,2

2

15

0,1

10 2

0,45 1

10

10

2

2

3

1

1

1

2

2

1

2

2

2

7,8

8,4

6,9

6

6,6

6,9

9,4

7,7

7 4,2

10,4 5,9

7,1

7,4

7,8

9,1

4,8

3,8

4,6

4,5

4

4,3

3,9

3,9

4,7

3,7

3,7

3,5

2,4

2,9

2,3

2,3

2,2

2,5

3,6

2,9

2,3

2,8

2,7

2,5

2,6

2,4

F

F

M

M

M

F

F

F

F

M

F

F

M

M

15

19

44

15

16

16

17

55

15

15

15

17

16

16

2

1

1

2

1

2

2

2

2

2

2

3

1

1

15

10

10

15

5

10

10

5

10

20

15

15

0,5

1

6,5

6,9

8,6

7,1

9,3

6,1

6,2

3,9

5,4

3,8

3,8

10,1 5,2

6,8 3,8

7,9

8,3

4,6

4,7

12,3 5,7

6,1

7

4,4

4,2

3,9

4

4,8

2,8

2,8

3,5

2,7

2,6

2,4

2,3

2,3

2,3

3,2

2,3

2,4

2,4

2,9

f

F

M

M

F

F

M

F

F

M

F

M

M

16

16

18

16

46

17

17

16

17

16

16

15

15

2

1

2

3

1

2

2

2

1

2

1

2

3

10

5

5

25

27

0,8

2

5

5

10

10

10

5

9,5

6,8

5,3

4,2

10,2 5,1

8,2 4,6

7,1

9,1

4,9

4,9

10,4 5

9,2 4,8

10,6 4,3

7,1

7,6

4,4

4,1

6,8

7,4

3,4

4,5

3,1

3

2,6

2,7

2,5

2,1

2,7

3

3

3,2

2,6

3,1

2,8

M

M

M

M

M

F

F

F

M

M

M

M

M

F

15

16

19

17

17

53

54

17

50

17

17

17

17

15

2

2

2

2

2

2

2

1

2

2

3

3

2

2

10

5

15

10

5

10

10

10

0,3

10

5

5

10

5

6,1

7,5

8

6,9

7,9

7,1

6,6

6,5

7

8,9

4,2

5,2

11,8 5,8

6,7 3,7

15,4 6,8

6,8 4,1

4,8

3,9

3,9

3,8

4,5

4,5

4,7

4,4

2,3

2,8

2,8

2,9

2,7

2,6

3,2

3,5

2,2

4,2

2,5

2,9

2,4

2,4

References

Ecological footprint analysis http://www.bestfootforward.com/resources/ecologicalfootprint/ http://www.epa.vic.gov.au/Ecologicalfootprint/calculator s/default.asp

http://footprint.wwf.org.uk/ http://myfootprint.org/en/about_the_quiz/what_it_measu res// http://www.bestfootforward.com/resources/ecologicalfootprint/

Scientific American Paper http://sams.scientificamerican.com/article/humans-notusing-more-than-one-planet/ http://www.statsoft.com/Textbook/Multiple-

Regression

Chap. 11: Simple Linear Regression

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