the consequences of child labor on the growth of human
TRANSCRIPT
THE CONSEQUENCES OF CHILD MARKET WORK ON THE GROWTH OF HUMAN CAPITAL
Armand A. Sim (SMERU Research Institute)
Daniel Suryadarma (Australian National University)
Asep Suryahadi (SMERU Research Institute)
July 2012
Introduction (1)
• About 218 million children <15 years old are working (ILO, 06).
– Most work in the family business or farm.
• Child labor is inefficient if it adversely affects future earning ability (Baland & Robinson, 00).
• Channels:
– School displacement (Grootaert &Kanbur, 95).
– In addition to affecting future earnings, schooling may also have positive externalities.
– Health risks associated with working (O’Donnell et al, 05).
Introduction (2)
• Literature on the effect of child labor on human capital is substantial (Basu, 99; Edmonds, 08).
• Ambiguous results.
– Working and schooling often go hand-in-hand.
– Child labor may provide sufficient additional income to keep children in school, buy food, and maintain their health.
• Issues to consider
– Effect of child labor may be long-term.
– Outcome indicators.
Wrong outcomes? (1)
• Most studies use school enrollment or attainment as a proxy for education.
• Issues with enrollment/attainment as an indicator
– A measure of input into the production function, not output (skills) (Gunnarsson et al, 06).
– In an environment where school quality is low, the correlation between input and output is low (Dumas, 08).
– Child labor may not affect enrollment/attainment, but time spent on studying, playing, and sleeping (Edmonds & Pacvnik, 05).
Wrong outcomes? (2)
• Some studies address health effects, using subjective well-being or height as indicators.
• Issues
– Subjective indicators.
– Height is determined very early on in a person’s life.
This study
• Measure the effect of child labor on the long(er)-term growth of human capital– Effect of child labor after seven years.
• Use better indicators– Mathematics and cognitive skills.
– Lung capacity – a measure of pulmonary function.
• Heterogeneity– Gender: boys and girls may be engaged in different kind of
jobs.
– Location: urban and rural labor markets may have a different effect.
– Type of work: for household business (generally unpaid) or for wage outside the household.
Outline
• Child market work in Indonesia
• Data
• Estimation strategy
• Estimation results
• Take home messages
Basic characteristics
• In 2007, about 2.7 million 5-14 year-olds were working.
• Related to poverty, adult unemployment, or stagnant economic growth (Kis-Katos & Sparrow, 11; Suryahadi et al, 05).
0
10
20
30
40
50
60
70
80
Male Female Male Female
2000 2007
Figure 5A. Three Most Popular
Occupation Sectors of Child Workers
2000 & 2007, by Gender
Agriculture, forestry, fishing and hunting
Manufacturing
Wholesale, retail, restaurants and hotels
0
1
2
3
4
5
6
7
8
9
10
Male Female Male Female
2000 2007
Figure 5B. The Rest of Occupation
Sectors of Child Workers 2000 & 2007,
by Gender
Mining and quarrying
Construction
Transportation, storage and communications
Finance, insurance, real estate and business services
Other services
National Labor Force Survey
0
5
10
15
20
25
30
Market
Work
Female Male Inside
Household
Outside
Household
Ho
urs
per
wee
k
Figure 4. Market Work Hours, by Gender and
Type, 2000 and 2007 Cohorts
2000 2007
Data (1)
• Indonesia Family Life Survey (IFLS)
– Panel dataset 1993, 1997, 2000, 2007.
– Represents 83% of Indonesian population.
– 7,200 hh in 93; 13,000 in 07.
– Low attrition: 5% per wave; 88% original households were interviewed in all subsequent waves.
• IFLS child labor module
– 2000 and 2007.
– All children 5-14 years old.
– Records market (economic) work both inside and outside of household.
– Economic work: production of economic goods and services.
Data (2)
• Definition of child labor– Market work in the past month.
– Alternative definitions: any market work that began when an individual is 5-14 (loose); market work in the past week (tight).
• Mathematics and cognitive skills (IFLS EK1)– 7-14 year-olds.
– 5 numeracy and 12 shape matching problems.
– Identical problems in 2000 and 2007.
– Test takers in 2000 asked to retake in 2007.
– Since tests are identical, any changes in performance measure actual skills growth over seven years.
Data (3)
• Lung capacity
– Peak flow meter – expiratory flow rate in liters/minute.
– Measures pulmonary function (Lebowitz, 91) and respiratory health (Rojas-Martinez et al, 07; Schwartz, 89).
– Depends on gender, age, height.
– Children living in environment with higher air pollution experience smaller lung capacity growth (He et al, 10).
Basic Model (1)
• Sample
– Child worker sample: those who were working in 2000.
– Comparison sample: those who were not working in 2000.
• Value-added model, condition for 2000 outcomes.
– Outcome variables normalized using 2000 standard deviation.
– W: Indicator for child worker, W = 1 for child workers.
Yijk,2007
s 2000
= f Wijk,2000,Yijk,2000
s 2000
,eijkæ
èç
ö
ø÷
Basic Model (2)
• Assumption for a causal interpretation of :
– Corr (W, ε|outcome 2000) = 0
• Examples where this would fail:
– Individual characteristics: age, sex
– Parental education
– General economic conditions
• A model that controls for these confounders would be:
W
Yijk,2007
s 2000
= f Wijk,2000,Yijk,2000
s 2000
,Xijk,Pijk,GDPk,1996,eijkæ
èç
ö
ø÷
IV Strategy (1)
• Many other confounders, some even unobserved.
– Example: community preference for education.
– Identification assumption may still be violated even after we control for observed characteristics.
• The strategy we use: instrumental variables.
– Find a variable that is correlated with W but uncorrelated with ε.
– The two conditions for a valid instrument: relevance and exclusion.
IV Strategy (2)
• Instruments used in the literature: – local economy, adult labor market conditions, or prices; school
quality and availability; household assets; compulsory school starting age.
• Our instrument– Basu (00): an increase in legislated minimum wage may increase
child labor under certain conditions, by affecting demand or supply of child workers.• Feature 1: child workers are not covered by the minimum wage
legislation.
• Feature 2: child labor can (perfectly) substitute adult labor, with a certain coefficient.
– Legislated minimum wage levels at the year and in the province a child worker began working.
– For non-child workers, we impute the year that they would have begun working based on birth year.
IV: Relevance
Dependent variable: Child labor status (=1) (1) (2) (3)
coef se coef se coef se
Provincial monthly legislated minimum wage (hundred
thousand Rupiah)
0.158** 0.051 0.307** 0.077 0.432** 0.058
Male (=1) 0.001 0.012 -0.001 0.013
Age in 2007 0.044** 0.005 0.049** 0.004
Father's schooling (years) -0.008** 0.002 -0.007** 0.002
District GDP per capita in 1996 (millions, 1993 Rupiah) -0.015** 0.006 -0.014* 0.006
Proportion of villages in the district with a market building 0.332 0.175
Proportion of villages in the district with year-round roads -0.039 0.139
Proportion of villages in the district with a formal financial
institution
-0.124 0.072
Proportion of villages in the district with a public health
center
-0.242 0.133
Number of primary and secondary schools in the district
(thousand)
-0.054** 0.019
Constant -0.109 0.067 -1.068** 0.159 -1.258** 0.186
Number of observations 2,675 2,675 2,675
R-squared 0.016 0.101 0.126
Notes ** p<0.01, * p<0.05; estimated using OLS; standard errors are clustered at the province level; the provincial minimum
wage depends on the year that a child worker began working or a non-child worker is predicted to have begun working
IV: Exclusion (1)
• Minimum wage legislation in Indonesia
– Based on a bundle of consumption items, around 2,600 –3,000 kcal/day (Suryahadi et al, 03).
– Up to 2000, each province has a single minimum wage level, determined through tripartite discussion.
– The minimum wage level in a province is a function of province-specific prices and negotiation results.
• Therefore, unlikely to have a direct causal relationship with the dependent variables.
IV: Exclusion (2)
• Correlation between minimum wage and ε:
– Fundamentally untestable, but we can still measure the correlation between minimum wage with several variables likely to be in the residual.
– Infrastructure – to measure unobserved economic-related factors.
– Availability of education and health facilities – proxy for unobserved community preferences.
– Labor market conditions and household expenditure data.
IV: Exclusion (3)
District Population Proportion of
villages in the
district with a
market building
Proportion of
villages in the
district with
year-round roads
coef s.e. coef s.e. coef s.e.
Provincial monthly legislated minimum wage
(hundred thousand Rupiah)
756,763.4 479,166.1 -0.008 0.108 -0.034 0.051
Constant -224,761.6 595,793.5 0.242* 0.136 1.001** 0.071
Number of observations 177 177 177
R-squared 0.097 0.000 0.009
Regression level District District District
IV: Exclusion (4)
Proportion of
villages in the
district with a
formal financial
institution
Proportion of
villages in the
district with a
public health
center
Number of
primary and
secondary
schools in the
district
(thousand)
coef s.e. coef s.e. coef s.e.
Provincial monthly legislated minimum wage
(hundred thousand Rupiah)
0.097 0.189 0.185 0.154 0.602 0.309
Constant 0.123 0.248 -0.076 0.194 0.005 0.382
Number of observations 177 177 177
R-squared 0.010 0.087 0.082
Regression level District District District
IV: Exclusion (5)
District Adult
Unemployment
Rate in 2000
Father is
employed in 2000
(=1)
Log of per capita
monthly household
expenditure in
2000
coef s.e. coef s.e. coef s.e.
Provincial monthly legislated minimum wage
(hundred thousand Rupiah)
0.032 0.017 0.007 0.062 0.044 0.154
Constant 0.018 0.021 0.554** 0.069 12.178** 0.204
Number of observations 177 2,614 2,641
R-squared 0.034 0.000 0.000
Regression level District Household Household
note: ** p<0.01, * p<0.05; standard errors are clustered at the province level; estimated using OLS.
How big is big?
• The dependent variable is in standard deviations.
• In education literature, 0.3 SD is considered a large effect.
• In Indonesia, one year of schooling produces 0.13 SD of math ability.
• In IFLS 2000, the difference between the median and the 75th
percentile is 1 SD.
Mathematics Skills Growth
Coefficient Std. Error
Child labor status (=1) -0.552* 0.266
Mathematics score in 2000, standardized 0.239** 0.033
Male (=1) -0.078** 0.029
Age in 2007 -0.001 0.011
Father's schooling in 2000 (years) 0.029** 0.006
District GDP per capita in 1996 (millions, 1993
Rupiah)-0.005 0.006
Constant 1.426** 0.159
Number of observations 2,675
Second stage R-Squared 0.066
First stage: F-statistics on instrument 16.166
Notes: ** p<0.01, * p<0.05; standard errors are clustered at the province level.
Cognitive Skills Growth
Coefficient Std. Error
Child labor status (=1) -0.476 0.370
Cognitive score in 2000, standardized 0.222** 0.033
Male (=1) 0.070* 0.031
Age in 2007 0.010 0.016
Father's schooling in 2000 (years) 0.024** 0.007
District GDP per capita in 1996 (millions, 1993
Rupiah)0.001 0.006
Constant 2.207** 0.255
Number of observations 2,675
Second stage R-Squared 0.080
First stage: F-statistics on instrument 16.193
Notes: ** p<0.01, * p<0.05; standard errors are clustered at the province level.
Lung Capacity Growth
Coefficient Std. Error
Child labor status (=1) -0.746* 0.331
Lung capacity in 2000, standardized 0.476** 0.039
Male (=1) 1.158** 0.034
Age in 2007 0.009 0.016
Father's schooling in 2000 (years) 0.010* 0.005
District GDP per capita in 1996 (millions, 1993
Rupiah)-0.022* 0.009
Constant 1.489** 0.228
Number of observations 2,675
Second stage R-Squared 0.485
First stage: F-statistics on instrument 16.084
Notes: ** p<0.01, * p<0.05; standard errors are clustered at the province level.
Gender heterogeneity
• No significant gender difference in child market work participation rate, type/place of work, or working hours.
• However, there is significant difference in sectoralcomposition of the occupation.
– Higher share of boys working in agriculture; higher share of girls working as housemaids.
• Even for children in the same sector, males and females may do different tasks (Edmonds, 08).
Mathematics Skills
Growth Cognitive Skills
Growth
Lung Capacity
Growth
CoefStd.
ErrorCoef
Std.
ErrorCoef
Std.
Error
MALE
Child Labor Status (=1) -0.302 0.293 -0.471* 0.238 -0.791* 0.344
N 1,365 1,365 1,365
R-Squared 0.099 0.032 0.110
First-stage F Statistics 13.406 13.700 12.932
FEMALE
Child Labor Status (=1) -0.910* 0.407 -0.557 0.716 -0.667 0.447
N 1,310 1,310 1,310
R-Squared -0.018 0.117 -0.014
First-stage F Statistics 13.787 13.055 13.596
Location heterogeneity
Mathematics Skills
Growth Cognitive Skills
Growth
Lung Capacity
Growth
CoefStd.
ErrorCoef
Std.
ErrorCoef
Std.
Error
RURAL
Child Labor Status (=1) -0.672* 0.274 -0.456 0.437 -0.516 0.412
N 1,526 1,526 1,526
R-Squared -0.008 0.080 0.493
First-stage F Statistics 13.994 13.526 13.018
URBAN
Child Labor Status (=1) -0.581 0.431 -0.772** 0.222 -1.099** 0.333
N 1,149 1,149 1,149
R-Squared 0.074 -0.021 0.476
First-stage F Statistics 22.616 23.125 24.966
Type of work heterogeneity
• Type of work in 2000:
– 87% work for the family business, usually unpaid.
– 20% work for wage outside family.
– 6% work both types
• Although unpaid, children working in the family business may face better conditions.
• This aspect of child labor is much less explored.
• Potential issue
– Choice of type of work may be endogenous.
– We do not model this choice.
Mathematics Skills
Growth Cognitive Skills
Growth
Lung Capacity
Growth
CoefStd.
ErrorCoef
Std.
ErrorCoef
Std.
Error
FAMILY
BUSINESS
Child Labor Status (=1) -0.785 0.427 -0.734 0.537 -1.104* 0.549
N 2,611 2,611 2,611
R-Squared 0.032 0.042 0.430
First-stage F Statistics 7.351 7.330 7.090
FOR WAGE OUTSIDE
Child Labor Status (=1) -1.253 0.691 -0.767 0.780 -1.401** 0.528
N 2,403 2,403 2,403
R-Squared 0.077 0.108 0.499
First-stage F Statistics 56.082 56.920 58.984
Conclusion (1)
• We find child market work to have a significant negative and large effect on growth of human capital over a seven-year period.– Similarly large for math skills, cognitive skills, and health.
• Gender heterogeneity– Male and female child workers suffer about the same in terms of
health and cognitive skills growth; statistically significant only for males.
– Female child workers suffer much worse in terms of mathematics skills growth.
• Type of work heterogeneity– Results only suggestive due to data and estimation difficulties.
– Child workers working for pay outside the household seem to bear worse effects of market work.
Conclusion (2)
• Take home messages:– Focusing on output measures of human capital unearth large negative
effects of child labor.
– These effects are observed even when 90% of the child workers are working for the family business, and 20% work outside the family.
– Even the “acceptable” child labor have severe detrimental effects on human capital.