Measuring the impact of intimate Measuring the impact of intimate partner violence against women on partner violence against women on victim’s and children’s well-being:victim’s and children’s well-being:An application of Matching An application of Matching Decomposition TechniquesDecomposition Techniques

Andrew MorrisonAndrew MorrisonMaria Beatriz OrlandoMaria Beatriz Orlando

Georgina PizzolittoGeorgina Pizzolitto

September, 2008September, 2008

Outline: IPV Impacts-MDT in Outline: IPV Impacts-MDT in PeruPeru MDT : non-parametric method –MDT : non-parametric method –

victims and comparison group non-victims and comparison group non-victimsvictims

Prior research on impacts of IPVPrior research on impacts of IPV Advantages of MDT to gauge Advantages of MDT to gauge

impactsimpacts DHS data for Peru: prevalence and DHS data for Peru: prevalence and

characteristics of victims/non-victimscharacteristics of victims/non-victims MDT description and resultsMDT description and results ConclusionsConclusions

Prior Research Definitions of Prior Research Definitions of IPVIPV

Types of Types of violenceviolence

PsychologicalPsychological PhysicalPhysical SexualSexual

Timing of Timing of violenceviolence

CurrentCurrent LifetimeLifetime

Prior Research MethodsPrior Research Methods

MethodsMethods Comparison of

means Simple correlations Bivariate and

multivariate logit/ probit regresions

Propensity score matching

Focus Groups and In-Depth interviews

DataData Victimization Victimization

SurveysSurveys DHSDHS WHO surveysWHO surveys

Prior research on the Impact of Prior research on the Impact of IPVIPV

Women’s control of reproduction Women’s control of reproduction and unintended birthsand unintended births

Use of Contraception (by type of Use of Contraception (by type of violence)violence)

Unintended birthsUnintended births STIs including HIV/AIDSSTIs including HIV/AIDS Evidence for Africa (Kishor and Evidence for Africa (Kishor and

Johnson, 2004) –but direction of Johnson, 2004) –but direction of causality unknowncausality unknown

Women’s mental and physical healthWomen’s mental and physical healthProblems walking, problems Problems walking, problems

carrying out daily activities, pain, carrying out daily activities, pain, memory problems, dizziness, memory problems, dizziness, vaginal discharge, emotional vaginal discharge, emotional distress distress

Visit a doctor, be hospitalized, or Visit a doctor, be hospitalized, or undergo surgery (Nicaragua). undergo surgery (Nicaragua). Effects are country specificEffects are country specific

Infant healthInfant health -Kishor and Johnson -Kishor and Johnson (2004)(2004)

Lower use of antenatal health Lower use of antenatal health care services care services

Increased the probability of a Increased the probability of a non-live birth (miscarriage, non-live birth (miscarriage, abortion or stillbirth)abortion or stillbirth)

May produce increases in infant May produce increases in infant mortality rates mortality rates

Advantages of using MDT: Advantages of using MDT: attribution, modeling, attribution, modeling, precisionprecision

Comparing women who suffer IPV with a Comparing women who suffer IPV with a control group of women who do not suffer control group of women who do not suffer IPV—but who are nearly IPV—but who are nearly identical over a identical over a range of measurable characteristicsrange of measurable characteristics

MDT does not require assumptions about MDT does not require assumptions about functional form required by multinomial logit functional form required by multinomial logit

MDT does not assumes a causal relation MDT does not assumes a causal relation between IPV and the outcome variablesbetween IPV and the outcome variables

More precise measurement of the More precise measurement of the explained explained and unexplained componentsand unexplained components of differences of differences

DataData

DHS Peru (2000)- violence module-DHS Peru (2000)- violence module- nationally representative. nationally representative.

All women between All women between 15 and 49 years 15 and 49 years oldold who are present in the household who are present in the household

Focused on Focused on violence by intimate violence by intimate partners and relativespartners and relatives (no questions (no questions about sexual violence)-about sexual violence)-physical physical violenceviolence. .

The survey did not ask about the The survey did not ask about the timing of the episodes -timing of the episodes -lifetime lifetime violenceviolence

Prevalence of domestic violence in Peru Prevalence of domestic violence in Peru (2000)(2000)Women aged 15-49 currently married or living with a Women aged 15-49 currently married or living with a partnerpartner

Intimate partner violence Prevalence

(%)

Ever experienced physical violence by partner 39.80

By age groups (years) 15-19 28.36 20-24 32.52 25-29 39.49 30-34 41.79 35-39 42.24 40-44 41.92 45-49 43.65

By educational level No education 42.04 Primary school 42.80 High school 41.21 Tertiary, College or more 28.93

Frequency of Husband getting drunk Never 24.59 Sometimes 41.08 Frequently 76.84

Punished or hurt by father as a child 67.72

Source: Own estimations based on DHS, Peru 2000

Decreases with age

Decreases with educationIncreases with alcohol consumption

Descriptive StatisticsDescriptive Statistics Women victims and non-victims of physical Women victims and non-victims of physical violenceviolence

Source: Own estimations based on DHS, Peru 2000

*** Significant at 1%, ** significant at 5%, * significant at 10%

DifferencDifferencee

AgeAge **

EducationEducation **

Punished Punished as Childas Child

**

Partner Partner EmployedEmployed

Husband Husband DrunkDrunk

**

Descriptive StatisticsDescriptive Statistics – Outcome – Outcome VariablesVariables

Source: Own estimations based on DHS, Peru 2000

*** Significant at 1%, ** significant at 5%, * significant at 10%

Victims of Pyisical Violence

Non victims of Physical Violence

Difference (Victims-Non Victims)

Weight *Height (centimeters* kilograms) 12328 12274 54.64 Amenia (severity degree) 29.88 32.50 -2.62 Number of Children 3.27 2.74 0.53***Number of children ever born 3.70 3.02 0.68***Last child wanted (%) 1.99 1.79 0.19***Terminated Pregnancies (%) 26.57 16.99 9.57***STD (%) 21.54 20.39 1.14* Delivey Complications (%) 42.75 32.86 9.89***

Visit health facility (%) 47.01 48.53 -1.52* Antenatal care (%) 97.80 97.45 0.34 Births assisted by health Care Professional (%) 52.20 54.20 -2.00* Unmet family planning needs (%) 13.16 15.32 -2.15***Contraceptive use (%) 90.21 86.00 4.20***

Employed (%) 70.35 64.05 6.29**

Outcome Variables

Women's Health

Women's use of health facilities

Women's Employment

Women

Descriptive StatisticsDescriptive Statistics – Outcome – Outcome VariablesVariables

Victims of Pyisical Violence

Non victims of Physical Violence

Difference (Victims-Non Victims)

Diarrhea (%) 20.17 13.69 6.48***Anemia (%) 75.06 73.50 1.56 Height*age 2009 2384 -375.0***Weight* height 6023.57 6216.14 -192.5** Inmunization (%) 40.96 33.73 7.22**Under 5 year mortality (per 1000 bitrths) 0.66 0.70 -0.04

Educational Gap (%) 54.89 61.32 -6.43**Schooll attendance (%) 88.23 85.46 2.76***

Use violence to discipline child (%) 50.13 37.26 12.86***

Children's educational achievement

Mother's using violence to discipline Child

Outcome VariablesWomen

Children's health

Source: Own estimations based on DHS, Peru 2000

Matching Decomposition Matching Decomposition Technique (MDT) Nopo 2004Technique (MDT) Nopo 2004

Using MDT women who experienced violence are matched to those who did not on the basis of their observable characteristics. The resulting matched females have exactly the same observable characteristics

Matching Decomposition Matching Decomposition Technique (MDT)Technique (MDT)

Step 1: Select one Step 1: Select one victim victim from the sample from the sample (without replacement)(without replacement)

Step 2: Select all the Step 2: Select all the non-victims non-victims that have the that have the same characteristics x as the same characteristics x as the victimvictim

Step 3: With all selected in Step 2, construct a Step 3: With all selected in Step 2, construct a synthetic individual whose characteristics are synthetic individual whose characteristics are equal to the average of all of them and “match” equal to the average of all of them and “match” her to the original her to the original victimvictim..

Step 4: Put the observations of both individuals Step 4: Put the observations of both individuals (the synthetic non-victim and the victim) in their (the synthetic non-victim and the victim) in their respective new samplesrespective new samples

The result is the generation of a partition of the The result is the generation of a partition of the dataset. Matched victims and non-victims have dataset. Matched victims and non-victims have the same empirical probability distributions for the same empirical probability distributions for characteristics x. characteristics x.

Unmatched victims (∆V)

Unmatched non-victims (∆NV)

Matched Victims and Non-victims (∆X , ∆0)

Variables included in control Variables included in control groups used in the matching groups used in the matching decompositiondecomposition

Source: Own estimations based on DHS, Peru 2000

1 2 3 4Age x x xNumber of Children x x xYears of education (women) x x xWas hurt by father or punished as childx x xSpousal Age Difference x x xSpousal Education Difference x x xHusband get Drunk x x xIncome level x

ControlVariable

Results from MDT- VictimsResults from MDT- Victims

Control 4

Weight *Height (centimeters* kilograms) 54.64 -0.002Amenia (severity degree) -2.62 0.034Number of Children 0.53*** 0.047**Terminated Pregnancies 9.57*** 0.080**Last child wanted (index: 1=wanted - 3=did not want more children) 0.19*** 0.006*STD (%) 1.14* -0.083*Delivey Complications (%) 9.89*** 0.020*

Visit health facility (%) -1.52* -0.030**Antenatal care (%) 0.34 -0.010Births assisted by health Care -2.00* -0.004Unmet family planning needs (%) -2.15*** 0.024Contraceptive use (%) 4.20*** -0.007*

Employed and earnning cash (probability) 6.29** 0.002

Women's use of health facilities

Women's employment

Outcome Difference (Victims-Non

Victims)

Delta Decomposition

(X)

Women's Health

Results from MDT- ChildrenResults from MDT- Children

Control 4

Diarrhea (%) 6.48*** 0.067*Anemia (%) 1.56 0.155Height*age (centimeters* age in months) -375.0*** 0.016*Weight* height (centimeters* kilograms) -192.5** 0.015*Inmunization (%) 7.22** -0.029Under 5 year mortality (per 1000 births) -0.04 0.012

Educational Gap -6.43** -0.002*Schooll attendance (%) 2.76*** 0.015*

Use violence to discipline child (%) 12.86*** 0.100**Mother's using violence to discipline Child

OutcomeDifference

(Victims-Non Victims)

Delta Decomposition(Delta X)

Children's health

Children's educational achievement

ConclusionsConclusions

In general, results are not robust to the In general, results are not robust to the use of different methodsuse of different methods

The MD technique is our preferred The MD technique is our preferred methodology.methodology.

– allows separating the impact of observable allows separating the impact of observable and unobservable factorsand unobservable factors

– takes into account that women who do and takes into account that women who do and do not suffer violence and female no do not suffer violence and female no violence have characteristics that are violence have characteristics that are distributed differently in their common distributed differently in their common support (Delta X).support (Delta X).

Naive comparisons shouldn’t be used Naive comparisons shouldn’t be used to formulate policyto formulate policy

Based on the MD technique, Based on the MD technique, IPV has:IPV has:

A strong negative impact on victim’s A strong negative impact on victim’s reproductive healthreproductive health

Negative impact on visits to health facilities Negative impact on visits to health facilities and use of contraceptivesand use of contraceptives

Negative impact on children’s healthNegative impact on children’s health with with the exception of immunizationthe exception of immunization

Children of women who are victims are Children of women who are victims are more likely to be in schoolmore likely to be in school

Strong evidence of intergenerational Strong evidence of intergenerational transmission of violencetransmission of violence