Does the Internet Make People Stay Home? Evaluating the Impact of the Internet on Vehicle Transportation and Motor Fuel Consumption
Penn State University
Xue “Snow” Dong
Outline of the Presentation
Previous Findings
Rationale of the study
Methods
Variables
Data
Model Selection
Results
Conclusion and Limitations
Previous Findings on Environmental Impacts
Positive impact of the Internet
Negative impact of the Internet
Rationale of the study
Methods
Variable
Specification
VMT per capita total VMT in each state divided by state population Motor fuel use per capita total motor-fuel use in each state divided by state population Internet use Gasoline price
percentage of people with access to the Internet (both dial-up and broadband) at home motor gasoline sales through retail outlets prices; There is no gas price data by state for the year 2011 and 2012; national average is used as a proxy.
Vehicle registration per capita vehicle registration in each state divided by state population Road density road length in each state divided by state area Gender Education Disposable income per capita
in thousand vehiclemiles in gallons in percent in U.S. dollars
in miles per sq. miles
percentage of male
in percent
percentage of people with bachelor's degree and above
in percent
disposable income per capita
U.S. dollars in thousands
Unemployment unemployment rate Population density state population divided by state area MPG
Unit
average U.S. light duty vehicle fuel efficiency
in percent population per sq. mile miles per gallon
Data
Panel data for the 50 U.S. states in 7 years: 2001, 2003, 2007, 2009, 2010, 2011, and 2012
50 × 7 = 350 observations
2 dependent variables
10 independent variables
Model Specification
vmtpcit = β1 + β2internetit + β3gaspriceit + β4vehiclepcit + β5roaddensit + β6genderit + β7eduit + β8incomepcit + β9unempit + β10popdensit + β11mpgit + Wit.
(1)
Where Wit = ci + Uit. mfuelusepcit = β1 + β2internetit + β3gaspriceit + β4vehiclepcit + β5roaddensit + β6genderit +β7eduit + β8incomepcit + β9unempit + β10popdensit + β11mpgit + Wit. (2)
Where Wit = ci + Uit.
Regression Diagnostics/Tests Multicollinearity (VIF
