VANESSA FRIAS MARTINEZ - a Scientific Researcher in the Data Mining and User Modeling Group at Telefonica Research in Madrid, Spain – focuses on technologies for emerging markets. She took participants through her work to determine specific human behaviors from cell phone data to evaluate the effectiveness of policy decisions. In order to measure the impact of the Mexican government’s H1N1 response in 2009, Vanessa analyzed call records to determine changes in people’s mobility patterns in Mexico City. The results indicated that the government’s policy to issue warnings to stay away from public spaces was in fact heeded by the citizens and thus effective in limiting exposure to the virus. Vanessa’s presentation also introduced cell phone data as cost-effective method to conduct demographic research in emerging economies. Paper: "Measuring the Impact of Epidemic Alerts on Human Mobility using Cell-Phone Network Data"

1. Enhancing Public Policy
Decision Making using Large-scale
Cell Phone Data
Vanessa Frias-Martinez
Telefonica Research
Madrid, Spain
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2. Cell Phones as Sensors
May 19, 2011, 7:06 pm The Sensors Are Coming!
By NICK BILTON
Telecom / Wireless
NEWS
Cellphones for Science
Scientists want to put sensors into everyone's hands
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3. Cell Phone Data: Calling Records
Calling Records are saved
by Telco Companies
Calling Records can be
anonymized
Calling Records are saved
for all feature and
smartphones (emerging
economies)
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4. Can cell phone data be used to
extract specific human
behaviors that might be useful
from a policy perspective?
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5. BEHAVIORAL Urban
CDRs VARIABLES Planning
Tools
Call Detail Consumption
Records Social
Mobility
Crisis
Management
Tools
Global Health
Tools
TELEFONICA RESEARCH INSTITUTIONS & POLICY MAKERS
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6. Cell Phone Data
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7. Modeling Behaviors
Consumption
• Number calls , duration, SMS/MMS/voice
• Expenses
• Handset Type and Features
Social
• Degree of the social network
• Weight of the contacts, frequency of communication
Mobility
• Diameter of mobility and social network
• Radius of gyration
• Mobility Patterns
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8. Computing Cost-Effective Census
Maps From Cell Phone Data
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9. Motivation: Census Maps
A/B
C+
C
D
E
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10. Motivation: Census Maps
A/B
C+
C
D
E
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11. Motivation: Census Maps
Expensive
Specially for
Emerging
Economies
(every 10 years)
A/B
C+
C
D
E
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12. Cell Phone Data as a proxy of SEL
Consumption
SEL PREDICTIVE
Social MODELS
Mobility
• Higher SELs are correlated to larger areas of mobility
• Lower SELs are correlated to smaller social network degrees
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13. CenCell Tool For Policy Makers
Accuracies up to 80%
13

14. Saving Budget
National Statistical Telcos build
National Statistical
Institutes carry out models to predict
Institutes carry out
surveys on a SELs from Cell
surveys
subset of regions Phone Usage
Predict the Present
Determine SELs for
non-surveyed
regions
SAVE
BUDGET
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15. Understanding the Impact of Health
Alerts using Cell Phone Data
15

16. H1N1 Mexico Timeline
Closed Reopen
Preflu 27th April 6th May
Alert Shutdown
17th April 1st May
Measure the impact that government alerts had on the population
16

17. Epidemic Disease Model
Contact Transition Recovery
Rate Rate Rate
Susceptible Exposed Infectious Recovered
All members within each compartment
are assumed to be equal
17

18. Agent-Based Model
Mobility Model
Social Network
Model
Disease Model
18

19. Discrete Event Simulator
M3 S3 D3
M2 S2 D2
M1 S1 D1
Social Network
Mobility Model Disease Model
Model
t₀ t₁ t₂ t₃ … t₉ (1 hour)
Using Calling Records from 1st Jan. till 31st.May 2009
Measure the impact that government alerts had on the
population’s mobility and on the disease’s spread 19

20. Impact On Population’s Mobility
April 27th May 1st May 6th
Mobility reduced between
10% and 30%
Alert Closed Shutdown Reopen
Intervention
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21. Impact on Disease Propagation
Baseline (“preflu” behavior all weeks)
Intervention (alert,closed,shutdown)
Epidemic peak postponed 40
hours
Reduced number of infected
in peak agents by 10%
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22. BEHAVIORAL Urban
CDRs VARIABLES Planning
Tools
Call Detail Consumption
Records Social
Mobility
Crisis
Management
Tools
Global Health
Tools
TELEFONICA RESEARCH INSTITUTIONS & POLICY MAKERS
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23. Scientific Publications
• Vanessa Frias-Martinez, Alberto Rubio and Enrique Frias-Martinez, "Measuring the
Impact of Epidemic Alerts on Human Mobility using Cell-Phone Network
Data", Second Workshop on Pervasive Urban Applications @Pervasive 2012,
Newcastle, UK
• Vanessa Frias-Martinez, Victor Soto, Jesus Virseda and Enrique Frias-Martinez,
"Computing Cost-Effective Census Maps From Cell Phone Traces",
Second Workshop on Pervasive Urban Applications @
Pervasive 2012, Newcastle, UK.
• Vanessa Frias-Martinez and Jesus Virseda and Enrique Frías-
Martínez, "SocioEconomic Status and Physical Mobility",Journal of Information
Technology for Development (ITD), Special Edition on "ICT and Human
Mobility: Cases From Developing Countries and Beyond", February Issue,
pages 1-16, 2012
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24. Scientific Publications
• Vanessa Frias-Martinez and Jesus Virseda,"On The Relationship Between Socio-
Economic actors and Cell Phone Usage", 3rd International Conference on
Information & Communication Technologies and Development, ICTD 2012,
Atlanta, USA.
• Enrique Frias-Martinez, Graham Williamson and Vanessa Frias-Martinez, "An
Agent-Based Model Of Epidemic Spread Using Human Mobility and Social
Network Information", 3rd International Conference on Social Computing
(SocialCom'11), Boston, USA, 2011
• Victor Soto and Vanessa Frias-Martinez and Jesus Virseda and Enrique Frias-
Martinez, "Prediction of Socioeconomic Levels using Cell Phone
Records", International Conference on User Modeling, Adaptation and
Personalization (UMAP), Industrial Track, Girona, Spain, 2011.
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25. Thanks !!
vanessa@tid.es
www.vanessafriasmartinez.org
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