heckle and chide: empowering matatu passengers to enforce better driving behavior in kenya james...
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Heckle and Chide:
Empowering matatu passengers to enforce
better driving behavior in Kenya
James HabyarimanaGeorgetown University
and
William JackGeorgetown University
Motivation• “Accidents happen!” he says, with a cheerful
shrug. "Maniacs? Maybe we are a little bit - but you've got to drive fast to get the money!”– A matatu driver in Kenya
• “Taxi drivers put money first and passengers' and pedestrians' lives second”– Patrick Ayumu, Ghana
Objectives of the project
• Evaluate a randomized intervention aimed at reducing matatu accidents by
– empowering passengers to….
– .…enforce better driving behavior
• Using evocative messages placed inside the matatu
WHY road safety?
• Major cause of injury and death– Rising share in global deaths
• Economically costly – 2% of national income in Kenya– Vulnerable population: working age (15-44)
accounts for 75% of RT fatalities (Odero (2003))
Source: Mathers and Loncar (2006)
WHY matatus ?
• They account for a large share of inter-city passenger transport– Vulnerable population in road traffic injuries
• They are involved in 20% of recorded crashes– But larger share of injuries/fatalities
• They are well suited to our intervention
WHY so many crashes?
• Road conditions
• Vehicle conditions
• Behavior of other road users
• Behavior of matatu drivers Focus ofstudy
WHO can affect driver behaviour?
Matatudrivers
Owners /Operators
Government(incl. police)
Passengers
Focus ofstudy
HOW do we empower passengers?
• Tell them to speak up!
• “Heckle and Chide”
• Insert stickers with messages inside matatus
WHICH stickers: heckle and chide imperatives?
WHICH stickers: The soft touch?
WHICH stickers: Shock therapy?
Sticker Placement Plan
Side door
Front ofmatatu
Driver’sseatAjaliFoot
Leg
Sit
Vibaya
HOW do we evaluate impact of the intervention?
• RCT– compare randomly selected matatus with
stickers to a control group of matatus without stickers
• Outcome measures– Crash rates
• Associated injuries/fatalities
– Survey results of passenger and driver behavior
Motivating the intervention
• Are accident rates efficient?– Collective action problems inside matatus
• If not, what is the role of regulation?– Enforcement problems in public regulation
• Stickers could either:– increase perceived benefit of action – if people
underestimate the effects of accidents; or– reduce the cost of taking action
• stickers legitimize heckling• Focal point for passenger action
Matatu-land, Nairobi
Recruitment
A challenging research environment
Outcome variable
Timeline
August 2007
March 2008
May 2008
Recruitment
Pilot recruitment • Weekly Raffles
• Accident Data Collection• Follow up surveys• Trip observations
January 2000
Data• Sample of 2,276 matatus from 21 SACCOs*
– 6 SACCOs account for about 50% of the sample• account for 166-312 vehicles
• 40% of sample had been assigned during pilot phase– Random assignment from SACCO lists to
treatment status: p=0.625
• 60% new matatus– assignment based on last digit of plate number– Odd Treatment– Even Control* Savings and Credit Cooperatives
03
06
09
01
20
# M
ata
tus
Control Treatment
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9
Compliance to assignment rule: New Matatus
Consent and Compliance
• Informed consent obtained from drivers
• Consent from owners very difficult
• Better compliance in pilot sampleShares of matatus that at least one sticker inserted
Assignment Entire Sample Old Sample New Sample
Control (no stickers) 0.16 0.06 0.22Treatment (stickers) 0.84 0.86 0.82Total 0.52 0.52 0.52
Partial compliancePercent receiving each treatment
Number of Stickers Control Treatment
0 84.4 16.1
1 0.3 3.6
2 0.2 3.1
3 0.5 8.0
4 0.1 0.7
5 14.5 68.5
Sample BalanceCovariates Control Treatment Difference
Significant
Owns cell phone0.89
(0.01)0.91
(0.01)No
Odometer reading356,506(7,236)
[327,365]
361,386(6,350)
[343,602]No
Capacity (passengers)14.52(0.05)
14.52(0.05)
No
Uses tout0.45
(0.02)0.48
(0.01)No
Number of weekly trips20.19(0.36)[14]
19.60(0.30)[14]
No
Average daily distance
420.48(6.14)[400]
414.10(5.33)[400]
No
Has speed governor1.00
(0.00)1.00
(0.00)No
Share owned by large Cooperative
0.49(0.02)
0.51(0.01)
No
Involved in accident in last 12 months
0.004(0.002)
0.015(0.004)
Yes
Selected Covariates COMPLIANT NON-COMPLIANTControl Treatment Control Treatment
Owns a cell phone 0.87(0.01)
0.92(0.01)
0.97(0.01)
0.84(0.03)
Odometer Reading 352773.86(7884.45)
[321587.00]
361055.90(6909.05)
[339677.50]
377001.21(18188.49)[401230]
363190.79(16168.82)[361696.5]
Passenger Capacity 14.54(0.05)
14.49(0.05)
14.43(0.13)
14.67(0.09)
Proportion use tout 0.45(0.02)
0.50(0.02)
0.40(0.04)
0.39(0.04)
Age, years 2.29(0.10)
2.78(0.10)
3.00(0.27)
2.67(0.23)
Number of weekly trips 20.22(0.40)[14]
19.72(0.32)[14]
20.00(0.87)[14]
18.95(0.74)[14]
Average daily distance, km
421.07(6.41)[400]
415.35(5.86)[400]
417.32(18.62)[400]
407.50(12.78)[400]
Proportion large Saccos 0.46(0.02)
0.51(0.02)
0.65(0.04)
0.51(0.04)
Proportion had accident in last 12 mths
0.005(0.002)
0.015(0.004)
0.00 0.011(0.008)
What drives selection into actual treatment?
Outcome data: accidents• Main outcome of interest is accidents
– Accident occurrence
– Severity - # injured, killed per accident
• Collected data from two sources
– Insurance companies• All vehicles are required to have minimal coverage• In theory all accidents should be observable – submission
of claims endogenous
– Our own data collection efforts
Other outcome data• Survey data from drivers and passengers to
assess behavior of both
– Safety of drivers
– Heckling and chiding by passengers
• Direct observation of driver behavior
– Send anonymous passengers on matatu trips?
Empirical Specification
• Difference-in-differences strategy to estimate – Parallel trends assumption
• Main concern is that treatment status is potentially endogenous
• Estimate intent-to-treat parameter
• Use assignment to treatment as instrument– IV estimates
Actual Treat status
Before(2007)
After(2008)
Difference
Control .045(.007)
.041(.006)
-.004(.009)
Treatment .057(.006)
.025(.005)
-.032(.007)
Difference .012(.009)
-.016(.007)*
-0.028(.012)*
Average treatment effect
Standard errors in parentheses, + significant at 10%; * significant at 5%; ** significant at 1%
Assignment Before After Difference
Control .045(.007)
.040(.006)
-.005(.008)
Treatment .057(.007)
.026(.005)
-.031(.008)
Difference .012(.01)
-.014(.008)+
-.026(.011)*
Intent-to-Treat Estimator
Standard errors in parentheses, + significant at 10%; * significant at 5%; ** significant at 1%
Actual Treatment Intent-to-Treat Instrumental Variables
(1) (2) (3) (4) (5) (6)
Post -0.005 -0.004 -0.005 -0.004 0.001 0.002(0.588) (0.662) (0.580) (0.654) (0.928) (0.840)
Treatment status 0.011 0.015 0.012 0.013 0.018 0.020(0.227) (0.116) (0.189) (0.155) (0.189) (0.161)
Post * Treatment -0.027 -0.028 -0.026 -0.027 -0.038 -0.040(0.026)* (0.021)* (0.032)* (0.025)* (0.032)* (0.025)*
Constant 0.045 0.034 0.045 0.034 0.042 0.031(0.000)** (0.001)** (0.000)** (0.001)** (0.000)** (0.007)**
Management Controls
X X X
Observations 4322 4318 4322 4318 4322 4318R-squared 0.003 0.013 0.003 0.013 0.003 0.013
Average Treatment Effects: LPM
P-values in parentheses, + significant at 10%; * significant at 5%; ** significant at 1%
05
10
15
20
Eve
nts
per
10
00
mata
tus
-4 -3 -2 -1 0 1 2 3Quarter since recruitment
Treatment Control
Quartely Events
Results so far
Claims rate
(% p.a.)
% Change over
baseline
Accidents avoided
Deaths/ injuries avoided
Baseline 5.1
Sticker effect
Average treatment effect -2.7 -53% ? ?
ITT /Reduced form -2.6 -51% ? ?
IV -3.8 -75% ? ?
Next Steps
• Examine data on possible mechanisms
• Collect more detailed claims data from insurance companies– Includes data on injuries – Types of events being affected by intervention
• Direct observation