DISCUSSION PAPER SERIESIZA DP No. 15531

Universal Early Childhood Education andAdolescent Risky Behavior

Michihito Ando
Hiroaki Mori
Shintaro Yamaguchi

SEPTEMBER 2022

DISCUSSION PAPER SERIESIZA DP No. 15531

Universal Early Childhood Education andAdolescent Risky Behavior

Michihito Ando
Rikkyo University

Hiroaki Mori

Senshu University

Shintaro Yamaguchi

University of Tokyo and IZA

SEPTEMBER 2022

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IZA DP No. 15531

SEPTEMBER 2022

ABSTRACT
Universal Early Childhood Education andAdolescent Risky Behavior*
The evidence for the effects of early childhood education on risky behavior in adolescenceis limited. This paper studies the consequences of a reform of a large-scale universal
kindergarten program in Japan. Exploiting a staggered expansion of kindergartens acrossregions, we estimate the effects of the reform using an event study model. Our estimatesindicate that the reform significantly reduced juvenile violent arrests and the rate of teenage
pregnancy, but we do not find that the reform increased the high school enrollment rate.
We suspect that improved non-cognitive skills can account for the reduction of risky
behavior in adolescence.
JEL Classification:

H52, I20, I28, J13, J24, K40

Keywords:

early childhood education, crime, teenage pregnancy

Corresponding author:
Shintaro Yamaguchi
University of Tokyo
7-chōme-3-1 Hongō
Bunkyo City
Tokyo 113-8654
JapanE-mail: syamaguchi@e.u-tokyo.ac.jp* This work was financially supported by JSPS KAKENHI (16K21743, 17K03795, 17K13747, 20H01510, 20K01733).
We are thankful for helpful comments from Nabanita Datta Gupta, James Heckman, Kristoffer Hvidberg, Nobuyoshi
Kikuchi, Stephan Litschig, Lester Lusher, Pi-Han Tsai, Weiqiu Yu, Jin Zhou, and seminar participants at the GRIPS,
Keio, Monash, Nazarbayev, AASLE Conference, EALE Conference, Econometric Society World Congress, IIPF Annual
Congress, Japan-Taiwan Seminar on Public Finance, JEA Fall Meeting, Kansai Labor Workshop, Kyoto Summer
Workshop on Applied Economics, SOLE Conference, Tokyo Labor Economics Workshop, and Trans Pacific Labor
Seminar. All conclusions, errors and omissions remain the responsibility of the authors.

1

Introduction

US President Biden’s American Families Plan envisions universal access to high-quality earlychildhood education. The economic case for promoting early childhood programs depends
on whether and how they benefit children and society at large. Risky behavior, including
criminal activity and teenage pregnancy, often leads to negative consequences, not only for theindividuals themselves but also for others in society, including their children (Anderson, 1999).
Given that risky behavior incurs large negative externalities, the efficacy of early childhood
education in reducing risky behavior can justify a policy intervention for early childhood
education accompanied by large public expenditures.
Despite their possible social benefits, the direct effects of early childhood education on risky
behavior are not well understood. Small-scale randomized studies targeting severely disadvantaged children, including the Perry Preschool Project (PPP) and the Carolina Abecedarian
Project (ABC), provide relatively compelling evidence for crime-reducing effects.1 However,
the efficacy of such programs may be substantially lower when they are expanded and serve a
different population. In fact, the existing evidence for large-scale programs is mixed. On the
one hand, Johnson and Jackson (2019) and Anders, Barr and Smith (Forthcoming) show that
Head Start, a large-scale targeted program, reduced crime, although the effect sizes are smaller
than those of the PPP and ABC. On the other hand, Baker, Gruber and Milligan (2019) find thatthe universal childcare program in Quebec had detrimental effects on children and increased
crime rates later in life. The effects of early childhood education on risky behavior can varyby scale of the program, population served, and other institutions in society. Although policy
makers around the world often rely on limited evidence from the US, existing evidence may notnecessarily be valid in other countries with different social contexts.
We attempt to fill this gap by estimating the effects of a kindergarten reform in Japan on
risky behavior in adolescence, including juvenile arrests and teenage pregnancy. There are atleast two reasons why studying the Japanese case can improve understanding of the efficacy ofearly childhood education. First, the kindergarten program in Japan is nationwide and universal.
Not only does the program accept children of all socioeconomic backgrounds, but its scale is
1See Heckman (2006), for example.

2

also much larger than that of Head Start in terms of enrollment: Approximately 1.7 million
children were enrolled in kindergartens in Japan at the end of the kindergarten reform in 1971,
while there were 397,500 children enrolled in Head Start.2 Second, Japan can be characterized
as having much lower rates of juvenile arrest and teenage fertility than are found in North
American countries (see Figure 1). Both of these factors can be expected to weaken the efficacy
of early childhood education in reducing risky behavior. If we find significant effects in sucha social context, we will gain greater confidence in early childhood education, which may help
policy makers in Europe and other parts of the world.
Figure 1: International comparison of juvenile arrests and teenage fertility

Notes: Panel A displays the arrest rate of men ages 15-19 in 1975 among OECD countries in the United
Nations Surveys on Crime Trends and the Operations of Criminal Justice Systems (UN-CTS). Panel B
compares the fertility rate of women ages 15-19 between 1970 and 1975 across these countries, basedon data from the United Nations World Population Prospects.

Japanese kindergartens provide formal pre-primary education, and their curriculum focuses
on fostering social-emotional skills rather than academic skills. In response to the recommendation of the United Nations Educational, Scientific, and Cultural Organization (UNESCO) in
1961, the national government promoted pre-primary education and increased the kindergarten
enrollment rate from 18 to 39% during 1964-1970. Exploiting staggered rollouts of the reform
across provinces3, we estimate the effect of the reform on juvenile risky behavior using an event
2 US Department of Health & Human Services (2022)
3 The actual administrative term used by the government is prefecture, but we use province as it is3

study model.
One of our main outcomes of interest is juvenile arrests because they incur large social costs,
and the prevalence of criminal offenses tends to peak in the late teens. Another outcome ofinterest is teenage pregnancy. Although teenage pregnancy itself is not necessarily problematic,
it is associated with weaker labor market outcomes and external costs, such as greater welfare
dependency. Furthermore, children born to adolescent mothers are more likely to experience
poor school performance, health problems, and criminal activity. Although it is not clear
whether such associations are causal, to the extent that they are, reducing teenage pregnancy
can improve the welfare of young women, their children, and society as a whole.
There are three reasons early childhood education may prevent risky juvenile behaviors.
First, early childhood education can increase years of education, mechanically reducing people’s
time to engage in behaviors that occur outside of school, including criminal and sexual activities.
This effect is known as the "incapacitation" or "incarceration" effect in the literature on juvenile
crime (Jacob and Lefgren, 2003) and teen fertility (Black, Devereux and Salvanes, 2008),
respectively. Second, by increasing years of education early childhood education can resultin higher earnings. This explanation is based on human capital theory, as increased humancapital raises the opportunity cost of risky behaviors after graduating from school. The third
explanation is related to non-cognitive skills. Childhood externalizing behavior, including
aggressive, antisocial, and rule-breaking behavior, predicts later antisocial behavior (Moffitt,1993). Early childhood education improves non-cognitive skills and eventually reduces risky
behaviors later in life (Heckman, Pinto and Savelyev, 2013).
We find that the kindergarten reform in Japan reduced the juvenile violent arrest and teenage
pregnancy rates significantly. The estimated effects on juvenile non-violent arrests are also
negative, but statistically insignificant with a large standard error. Our estimates indicate thatthe kindergarten reform decreased the juvenile violent arrest and teenage pregnancy rates by
1.052 and 1.325 per 1,000 individuals, respectively. In other words, the reform reduced theseoutcomes by 38% and 17% from their pre-reform averages, respectively. This result implies thata large universal early childhood education program can reduce risky behavior later in life, evenmore intuitive to most readers. Japan has 47 provinces that constitute its first level of administrative andjurisdictional division.

4

in a country with very low rates of crime and pregnancy among adolescents, and should give
policy makers around the world greater confidence in the efficacy of early childhood education.
To investigate the underlying mechanisms at work here, we also estimate the effects of
the kindergarten reform on high school enrollment. High school is not part of compulsory
education in Japan and 92% of the children affected by the kindergarten reform were enrolled
in high school during the analysis period. We do not find that the kindergarten reform increased
high school enrollment, which implies that additional schooling is unlikely to be a channel
through which early childhood education reduces risky behaviors.
Although we do not have a measurement for non-cognitive skills, Yamaguchi, Asai andKambayashi (2018b) find that the universal childcare program in Japan, which shares similar
curriculum standards with kindergartens, reduces aggressive behavior among children with
low-educated mothers. These findings might collectively suggest that a plausible explanation
for the effect of preventing risky behavior is the development of non-cognitive skills.
We address possible endogeneity biases by testing pre-trends, conducting falsification tests,
and estimating several alternative models. First, we do not find a significant pre-trend in theevent study model. Second, we conduct a falsification test in which the outcome variables arecrime and pregnancy rates of older cohorts that are not directly affected by the reform. If a labormarket shock or an unmeasured policy change affects criminal behavior and pregnancy and iscorrelated with the reform, our estimates are biased. To the extent that it affects both adolescentsand adults in a given year, our falsification test can detect the existence of a confounder. Third,
we address four issues including inter-regional migration, endogenous kindergarten enrollment,
and the existence of other confounders by using alternative specifications, but our main results
remain essentially unchanged.
The remainder of this paper proceeds as follows. We review the related literature in Section
2. Section 3 describes the institutional background in Japan and the kindergarten reform.
Section 4 explains our empirical strategies. Section 5 describes the data. Section 6 presents theresults. In Section 7, we perform several specification checks. We discuss potential mechanisms
in Section 8 and conclude in Section 9.

5

2

Related LiteratureThis paper contributes to the large literature on early childhood education. Previous research
focuses mainly on short-term cognitive and non-cognitive outcomes4 and long-term outcomessuch as educational attainment and labor market outcomes.5 These studies established evidence
that early childhood education can improve these outcomes; however, the evidence for earlychildhood education reducing risky behavior is limited and concentrated in targeted programsin the US such as the PPP, ABC, and Head Start.
Heckman et al. (2010) find that participation in the PPP significantly decreased felonyarrests. The Chicago Child-Parent Center (CPC) preschool program reduced felony arrests
especially among children of high school dropouts (Reynolds et al., 2011). García, Heckman
and Ziff (2019) also find that the ABC significantly reduced criminal activities, particularly forthe least advantaged children. Recent studies on the effects of Head Start on criminal behavior(Johnson and Jackson, 2019; Anders, Barr and Smith, Forthcoming) find a significant reduction
in incarceration and serious convictions. All of these programs are targeted at poor children,and hence it is not entirely clear whether the demonstrated effects can be maintained when aprogram serves non-poor children as well as poor children.
Indeed, the evidence for a universal program is mixed. Anders, Barr and Smith (Forthcoming) estimate the effects of the Smart Start Program, a universal program in North Carolina,
and find a significant decrease in serious convictions. Baker, Gruber and Milligan (2019) study
the long-term effects of the universal childcare program in Quebec, Canada. They found thatcohorts with greater access to universal childcare in Quebec experienced a higher, instead ofa lower, crime rate later in life. Both of these papers study programs in North America, andthe evidence from these programs may or may not be applicable to other countries because
4 See Gormley and Gayer (2005), Baker, Gruber and Milligan (2008), Datta Gupta and Simonsen(2010), Kottelenberg and Lehrer (2017), Cornelissen et al. (2018), Carta and Rizzica (2018), Felfe andLalive (2018), Yamaguchi, Asai and Kambayashi (2018a,b), Cornelissen and Dustmann (2019), Fort,
Ichino and Zanella (2019), Drange and Havnes (2019), Cascio (2020), Kose (2021), and Rege et al.
(2021), for example.
5 See, for example, Berlinski, Galiani and Manacorda (2008), Havnes and Mogstad (2011a,b, 2015),
DeCicca and Smith (2013), Akabayashi and Tanaka (2013), Felfe, Nollenberger and Rodríguez-Planas(2015), Drange, Havnes and Sandsør (2016), Datta Gupta and Simonsen (2016), Herbst (2017), GrayLobe, Pathak and Walters (2021), Bailey, Sun and Timpe (2021), and Kawarazaki (2022).

6

institutions and contexts differ.
This paper is also related to the literature on the effects of education on teenage pregnancy.
Several papers in the literature estimate the effects of an additional year of education on teenage
pregnancy by exploiting changes in compulsory schooling laws in different countries.6 To theextent that early childhood education improves cognitive and non-cognitive skills, it is likely toeventually prevent risky behavior such as teenage pregnancy as well as crime. However, evidence
for early childhood education reducing teenage pregnancy is scarce, mixed, and limited to the
US. Berrueta-Clement et al. (1984) and Campbell et al. (2002) find that the PPP and ABC
reduced teenage pregnancy, respectively, but Campbell et al. (2008) find that Project CARE, arandomized study in North Carolina, had insignificant effects.
Our contribution is to offer new evidence for early childhood education preventing crime andpregnancy among adolescents in a country with different institutions and social contexts than arefound in the places where the existing evidence was gathered. First, the Japanese kindergarten
program was universal and far larger than programs studied in the previous research. This
program accepted all children regardless of socioeconomic status. In terms of enrollment size,
the Japanese program was four times greater than the US Head Start program during the analysis
period. Second, the rates of juvenile arrest and teenage fertility were much lower in Japan thanin North America. Both factors are expected to reduce the effectiveness of a program. Our
positive result suggests that early childhood education can prevent risky behavior of adolescentseven in such a context and therefore should give policy makers outside the US added confidence
in the efficacy of early childhood education.

3

Institutional BackgroundWe describe the institutional characteristics of Japanese kindergartens in Section 3.1. The
national curriculum, which was developed under the strong influence of the US during the US
occupation of Japan, emphasizes children’s socio-emotional skills rather than their academic
6 Examples include, but are not limited to, the US (Black, Devereux and Salvanes, 2008; McCrary

and Royer, 2011), U.K. (Geruso and Royer, 2018), Germany (Cygan-Rehm and Maeder, 2013), Sweden
Grönqvist and Hall (2013), Norway (Black, Devereux and Salvanes, 2008), and Canada (DeCicca andKrashinsky, 2020).

7

skills. We then outline the kindergarten reform of 1964-1970 in Section 3.2. This reform
allowed more than 1.4 million children to enroll in kindergartens throughout the country.

3.1

Kindergartens in Japan

While most countries offer early childhood education and care (ECEC) in a unified framework,
Japan provides kindergartens and center-based childcare as distinct ECEC institutions (OECD,2015). The main objective of kindergartens is to provide formal pre-primary education tochildren over the age of 3 regardless of their parents’ employment status. Kindergartens offer ahalf-day (at least 4 hour) program. In contrast, center-based childcare offers a full-day programfor children ages 0-6, and both parents being employed is virtually required for its use. Neither
kindergartens nor center-based childcare are means-tested.
ECEC is heavily subsidized by the government, and therefore kindergarten fees are highly
affordable, although they vary according to several factors, including province of residence,
household income, and number of siblings. In 1970, the average annual out-of-pocket fee forpublic and private kindergartens was 14,520 JPY and 37,920 JPY respectively, which amounted
to about 1-3% of average household income.7
All public and private kindergartens are subject to quality regulations, including national
curriculum standards and teacher certification requirements. The Ministry of Education firstdeveloped the national curriculum guidelines in 1947 during the American occupation ofJapan with the advice of Helen Heffernan, who served as the chief of rural and elementary
education for the California State Department of Education during 1926-1965 (Blackwood,
1988; Weiler, 2011). These guidelines later became the foundation of the national curriculum forkindergartens, which has been implemented since 1956 with minor revisions. This curriculum
specifies key experiences in children’s development and emphasizes hands-on activities amongchildren, rather than teacher-driven instruction. Similar to the HighScope curriculum and theHead Start framework, the Japanese kindergarten program focuses on fostering social-emotional
7Note that 1970 is the last year of the kindergarten reform on which we focus in Section 3.2. According

to the Household Survey, the average annual income of working households with two or more people
was 1,355,388 JPY (i.e., 112,949 JPY per month ⇥ 12 months) in 1970. See Ministry of Health andWelfare (1971) for more details regarding kindergarten fees.

8

skills rather than academic skills. In addition, since 1954, all kindergarten teachers must havea national license for kindergarten teachers that requires at least two years of post-secondary
education.
The maximum student-teacher ratio in each kindergarten classroom was first required to be
40 to 1 in 1956 and this requirement has been modified to 35 to 1 since 1995. In practice, theclass size constraint seldom holds in kindergartens. Japan complied with the recommendationof the International Conference on Public Education in 1961 that the student-teacher ratio
for pre-primary institutions should be below 25 to 1 (IBE-UNESCO, 1961). The average
student-teacher ratio was 24 to 1 during 1957-1985, but this was higher than in other countries.
For example, Havnes and Mogstad (2011b) report that the student-teacher ratio in Norwegianchildcare centers was between 17 and 19 to 1 for children over 3 years of age during 1975-1981.
Head Start recommends that class sizes for children ages 4-5 range between 17 and 20 (Carneiro
and Ginja, 2014). Appendix A provides more details on the institution of kindergarten in Japan.

3.2

Kindergarten Reform in 1964-1970

The regional gaps in kindergarten availability were substantial in the early 1960s; while thenumber of kindergartens gradually increased after World War II, 1,709 out of 3,388 municipalities still did not have any kindergarten before 1966 due to insufficient financial support fromthe national government.8 Following the recommendations to promote pre-primary educationin 19619, the national government reformed its pre-primary education policy by heavily subsidizing the construction and expansion of kindergartens during 1964-1970. The goal was toestablish at least one kindergarten in all municipalities with more than 10,000 residents.10
This reform successfully increased the number of kindergartens by 45% (from 7,687 to
11,180) and the number of kindergarten teachers by 84% (from 37,041 to 68,607) between 1963
and 1971. Most of the newly created kindergarten slots were immediately filled. In fact, manykindergartens remained oversubscribed even after the reform. The median child-to-slot ratio in
1965 was 113 % and remained almost the same at 110 % in 1971.
8 Ministry of Education (1979)
9 IBE-UNESCO (1961)
10 Ministry of Education (1979).

9

Although all children ages 3 to 5 were eligible for kindergarten, the typical kindergarten
starting age was 4 during and after the reform. Figure 2 shows that the fraction of children
starting kindergarten at age 4 increased dramatically during the reform, while the trends forother ages remained relatively stable. Consequently, the kindergarten enrollment rate at age 4
doubled from 18.4 % in 1963 to 41.3 % in 1971.11
Figure 2: Percentage of children entering kindergarten at ages 3-5, 1955-1980
40

Entered at age 430

20Entered at age 5

10Entered at age 3

0
1955

1960

1965

1970

1975

1980

Year

Notes: This figure displays the fractions of children entering kindergarten at each age between 3 and 5.
The gray-colored area corresponds to years during the kindergarten reform. To calculate the number ofchildren entering kindergarten at age 4 in year C, we subtract the number of 3-year-old kindergarten
students in year C 1 from the number of 4-year-old kindergarten students in year C, assuming that nochildren who entered kindergarten at age 3 dropped out. The number entering at age 5 is calculated in asimilar manner. The number entering at age 3 is equal to the number of 3-year-old students askindergartens only accept children who are at least 3 years old.

Despite the rapid increase in kindergarten enrollment, the reform does not appear to havecompromised the quality of kindergartens. For example, the average ratio of kindergarten
students to teachers changed very little from 24.9 in 1963 to 25.4 in 1971.12 The stability of thestudent-to-teacher ratio suggests that the increase in enrollment during the reform did not cause
substantial crowding in kindergartens.
11See Figure B.2 for variations in the kindergarten enrollment rate at age 4.
12 Based on data from the School Basic Survey, we calculate an average ratio of kindergarten students toteachers in each province as the ratio of the number of kindergarten students to the number of kindergarten
teachers.

10

4Empirical Strategy

To identify the causal effects of the kindergarten reform, we exploit inter-provincial variationsin the growth of the kindergarten enrollment rate for 4-year-old children during 1964-1970.
Section 4.1 describes the growth of the kindergarten enrollment rate across provinces anddiscusses possible determinants of the reform rollout. Specifically, we examine the correlations
between the growth of the kindergarten enrollment rate and pre-reform provincial characteristics
such as the provincial GDP. In Section 4.2 we specify our econometric model based on the event
study approach. Section 4.3 discusses possible threats to the identification strategy and explains
how we validate the parallel trend assumption.

4.1

Regional Variation in the Reform Rollout

The kindergarten reform caused substantial variations in the growth of kindergarten enrollment
across provinces. As Figure 3 indicates, some provinces increased the enrollment rate by morethan 40 percentage points, while growth in other provinces remained as low as 8 percentage
points. Provinces with high enrollment rates before the reform tended to exhibit a higher
growth rate. The growth rate was notably higher in Tokyo and surrounding provinces, including
Kanagawa, Chiba, and Saitama, whereas it was lower in the western region, including theprovinces of Osaka, Kyoto, Hyogo, Aichi, and Fukuoka. Figure B.1 reports how the kindergarten
enrollment rate varied before and after the reform in each province.
A plausible explanation for these regional variations is that provincial and municipal governments had a certain level of discretion in expanding kindergartens. In particular, while thecentral government pursued a reform initiative and offered subsidies to local governments, local
governments were responsible for implementing the reform and determining the appropriate
level of kindergartens given their local needs.
We take advantage of the differences in the growth of kindergarten enrollment acrossprovinces in the reform period to construct a treatment variable. To shed light on the determinants of kindergarten enrollment growth during the reform, we examine the correlations
between the growth of the kindergarten enrollment rate and pre-reform provincial characteristics

11

Figure 3: Geographical variation in the growth of the kindergarten enrollment rate during thekindergarten reform

40
30
20
10

Notes: This figure shows variations in the kindergarten enrollment rate during 1963-71 for 46
provinces. We omit the province of Okinawa due to missing data.

including real provincial GDP per capita and fiscal capacity. To measure the fiscal capacityof a province we use the amount of fiscal-equalization grants. Fiscal-equalization grants forprovinces are transfers from the central to provincial governments and cover provincial fiscal
needs that cannot be covered only by provincial tax revenues, so provinces with higher fiscal
capacities typically receive a relatively small amount of fiscal-equalization funding from thecentral government.
We note three findings in Table 1. First, the growth of the kindergarten enrollment rate is
positively correlated with the pre-reform kindergarten enrollment rate (see column 1). Second,
the growth of the kindergarten enrollment rate is positively correlated with the real provincial
GDP per capita (column 2) and negatively correlated with the amount of fiscal-equalization
grants (column 3). Together, these patterns suggest that the major provinces with greater fiscal
capacity experienced a higher growth in kindergarten enrollment.
These results indicate that the growth of the kindergarten enrollment rate is not random.
Note, however, that randomness is not required for identification. Our identification is based

12

Table 1: Correlation between reform rollout and pre-reform provincial characteristics(1)
Kindergarten enrollment rate in 1960

(2)

(3)

(4)

(5)

(6)

0.632
(0.145)

Real Provincial GDP per capita in 1960

0.955
(0.357)0.012(0.007)

Fiscal-equalization grants per capita in 1960

(7)

-0.034(0.016)-0.615(0.241)-0.593(0.308)Low-educated women’s share in 1960

-0.531(0.333)-0.242(0.347)Growth in low-educated women’s share during 1950-1960

0.457(1.854)0.131(1.352)

Women’s employment rate in 1960

-0.201(0.143)0.014(0.184Growth in women’s employment rate during 1955-1960-0.146(0.557)-0.680(0.447)

Child population ratio in 1960

-0.125(0.055)-0.025(0.071)

Growth in child population ratio during 1955-1960-0.297(0.328)-0.737(0.329)Notes: This table shows slope estimates obtained from a simple regression of the growth in thekindergarten enrollment rate during the reform on the pre-reform provincial characteristics. See Table
B.2 for definitions and data sources of the provincial characteristics. Heteroskedasticity-robust standard
errors are reported in parentheses.

on the difference-in-differences design, and hence the key identifying assumption is a parallel
trend assumption conditional on a set of control variables. We assess the plausibility of theparallel trend assumption by examining the existence of a pre-intervention trend using the event
study model laid out in Section 4.2.

4.2

Econometric Model

We estimate the causal effects of the kindergarten reform using the following event study model:

.8C =

’

⌘2{1967,...,1995}{U⌘ ⇢=A>;;8 ⇥ 1[C = ⌘] + V ⌘ -8 ⇥ 1[C = ⌘]} + c8 + `C + Y8C ,(1)

where .8C is an adolescent outcome variable such as the juvenile arrest rate in province 8 in year
C. The treatment variable denoted by⇢=A>;;8 is the growth of the kindergarten enrollment

rate during the reform period in province 8. Note that the treatment variable is continuous.
The indicator function 1[C = ⌘] takes the value of one if the condition in the square brackets

13Figure 4: Pre-reform, phase-in, and post-reform periods for adolescent outcomes
Reform cohorts

1960

1966

Birth year

1974
1985

Year of reaching 14 years oldYear of reaching 19 years old

1974

1985

Pre-reform period Phase-in periodYear

Post-reform period

Notes: This figure defines the pre-reform, phase-in, and post-reform periods for evaluating the effects of
the kindergarten reform on adolescent outcomes among individuals ages 14-19. We refer to individuals
born between 1960 and 1966 as “reform cohorts” as they may have entered kindergarten at age 4 during
the reform. Accordingly, for adolescent outcomes we define the period of 1974-1985 as the “phase-in
period” because the reform cohorts reached ages 14-19 during this period. Years before and after thephase-in period are defined as the “pre-reform period” and “post-reform period”, respectively.

is satisfied and the value of zero otherwise. The coefficient U⌘ captures the time-varying
effect of the kindergarten reform. To control for preexisting differences in outcome trends
across provinces, we include -8 , the pre-reform provincial characteristics listed in Table 1. The
parameters c8 and `C are province-specific fixed effects and year fixed effects, respectively. The
variable Y8C is an idiosyncratic error.
For normalization, we assume that U1973 = V1973 = 0 for adolescent outcomes because
individuals exposed to the kindergarten reform would have begun to reach adolescence 10 years
after the reform began in 1964. As illustrated in Figure 4, we refer to those born between 1960
and 1966 as the “reform cohort” because they were four years old and eligible for kindergarten
during the reform period, 1964-1970. Consequently, we define the period 1974-1985 as the“phase-in” period of the reform, because the reform cohort reaches ages 14-19 during thisperiod. In addition, we refer to the years prior to the phase-in period as the “pre-reform” period
and the years after the phase-in period as the “post-reform” period. As such, the estimatesU⌘ for the pre-reform (⌘ < 1973) period capture a pre-trend, while those for the phase-in(1974  ⌘  1985) and post-reform (⌘ > 1985) periods are interpreted as the dynamic effectsof the kindergarten reform.

14

4.3

Threats to Identification

Our key identification assumption is the parallel trend assumption. We assess the plausibilityof this assumption by examining the presence of a pre-treatment trend, but there are several
remaining concerns for identification.
One of the threats to our identification strategy is the possible influence of policy changes
other than the kindergarten reform. If there were concurrent policy changes that were likely
to influence juvenile crime and teenage pregnancy, we cannot disentangle the effects of thekindergarten reform from other policy changes. Apart from the kindergarten reform, we are notaware of any substantial changes in the criminal justice system or abortion law during the analysis
period. For example, the Juvenile Act, established in 1948, stipulates nationally standardized
criminal procedures for juvenile offenders. It was revised in April 2001 to allow criminal
charges to be imposed on offenders ages 14-15, but this is outside the analysis period (19671995);13 Similarly, the Maternity Protection Act, which legalized induced abortions among
mothers until the second trimester of pregnancy (22 weeks), was enacted in 1948. During
1948-1952, performing induced abortions required a review by a regional abortion committee.
The abortion law was revised in 1952 to permit designated medical doctors to perform abortion
surgeries at their discretion. Since then, there has been no substantial revision to the abortion
law, including within the analysis period.
Although there seem to have been no substantial policy changes, we may have missed somepolicy changes at the local government level. To address this concern, we perform placebo tests
in which we take as outcomes the arrest and pregnancy of older cohorts who were not directly
affected by the kindergarten reform. To the extent that an unobserved policy change influences
not only adolescents but also older cohorts, we are able to detect such a policy change biasing
our estimates. Furthermore, our placebo tests can detect other confounders as long as theyaffect both adolescents and older cohorts. An example of such confounders is a local economic
condition or a labor demand shock. We will discuss the placebo tests extensively later in Section
7.1.
Inter-provincial migration is another threat to identification. If crime-prone youth are more
13 Oka (2009) provides background of this revision.

15

likely to move to urban regions where the growth of the kindergarten enrollment rate is high,the estimates may be biased upward. Yet another concern about biased estimates arises fromthe fact that kindergarten enrollment is an endogenous decision by parents. Furthermore, oureconometric model may not be correctly specified and some relevant variables may have been
omitted from the regression model. We discuss these concerns extensively in Section 7.2.

5

Data

We construct panel data from 46 Japanese provinces, excluding the province of Okinawa because
data were unavailable from this province until the 1970s. Our main outcome variables include
juvenile arrest and teenage pregnancy rates. We also take the high school enrollment rate, thecenter-based childcare enrollment rate, and the female employment rate as additional outcome
variables that facilitate the interpretation of the main results. We report the summary statisticsof the key variables in Table 2 and provide the remaining details of the data in Appendix B. We
describe juvenile arrest and teen pregnancy rates below, as they are our main outcomes. Other
variables are briefly explained as they are introduced in the analysis.
Juvenile arrests are of primary interest to us because they involve large social costs andthe prevalence of criminal offenses tends to peak in the late teens (Anderson, 1999). Juvenilesuspects in Japan are released, placed on probation, sent to a juvenile correction center, or sent
to prosecutors to be considered for criminal charges after receiving investigations from policeand domestic court. Under the Juvenile Act, individuals ages 13 and younger are protected frombeing processed in the juvenile justice system. Individuals ages 14-15 years can be processedin the juvenile justice system while being exempted from criminal charges to avoid depriving
them of the right to receive compulsory education. Offenders ages 16-19 are subject to criminal
charges.
Our data are taken from administrative records, allowing us to avoid desirability and/or
recall biases seen in self-reported surveys. Indeed, Kling, Ludwig and Katz (2005) documentthat young people tend to underreport their involvement in antisocial activities such as criminalarrests. We define a juvenile arrest rate as arrests per 1,000 people ages 14-19 in a given year.

16Violent offenses include assault, assembling with offensive weapons, arson, murder, robbery,rape, criminal intimidation, and extortion. The non-violent arrest rate includes all other arrests
including those for traffic violations. The juvenile arrest rate for violent crimes was 2.183
per 1,000 individuals per year during the analysis period from 1955 to 1995. The juvenile
non-violent arrest rate was much higher at 16.875 per 1,000 individuals. To place Japan in
the international context at that time, we compare the juvenile arrest rate between countries.
Japan’s juvenile arrest rate in 197514 was 24.4 per 1000 men, which amounts to 60% of that in
Norway, 38% of that in Canada, and 32% of that in the US (see Figure 1). Therefore, Japan had
a relatively low juvenile arrest rate.
Another main outcome variable is the teenage pregnancy rate. Unlike juvenile arrests,
teenage pregnancy is not necessarily undesirable, but is associated with many long-term economic and health disadvantages for both mothers and children, such as dropping out of highschool, poverty, participation in crime, low birth weight, and a higher infant mortality rate. We
define the teenage pregnancy rate as the total number of childbirths and induced abortions per
1,000 women ages 15-19 in each year. Numbers of births and induced abortions are taken fromadministrative records. Miscarriages and stillbirths are not considered in this paper because ofa lack of data for early-stage miscarriages. Induced abortion is legal in Japan and designatedmedical doctors can perform abortion surgeries at their discretion. Doctors are required bylaw to report each abortion case to the local office of the Japan Association of Obstetricians
and Gynecologists. Given these circumstances, we believe that unreported cases are rare. We
observe induced abortions among women ages 15-19 between 1970 and 1995, but not for theperiod 1967-1969. For these three years, we impute induced abortions among women ages
15-19 by multiplying the overall induced abortions in each year during this period by the shareof induced abortions among women ages 15-19 in 1970. The teenage pregnancy rate during theanalysis period was 8.990.
We could not find statistics for teenage pregnancy that allow international comparison in theanalysis period, but teenage birth rates are available. From 1970 to 1975, the birth rate per 1,000
women ages 15-19 was 61.4 in the US, 32.5 in Norway, and 37.2 in Canada. Given that these
14 Note that 1974 was the first year when individuals directly affected by the kindergarten reform

reached age 14 and could thus be arrested as juvenile offenders.

17statistics can serve as lower bounds for teenage pregnancy rates, Japan’s teenage pregnancy rate
was much lower at 4.6 (see Figure 1).
Table 2: Summary statistics of selected variables
Obs.
(1)

Pre-reform average(2)Overall average(3)

Juvenile risky behavior
Juvenile violent arrest rate (per 1,000 individuals)

1334

Juvenile non-violent arrest rate (per 1,000 individuals)

1334

Teenage pregnancy rate (per 1,000 women)

1334

2.743
[1.427]14.000[4.466]
7.857[2.779]2.183[1.182]
16.875[4.565]8.990[3.064]

Other outcomes
Enrollment rate for center-based childcare (%)

1334

11.191[7.411]23.034[11.247]
82.320[8.181]83.373[8.444]52.786[12.976]

19.981[12.685]
56.396[25.911]91.210[6.159]92.982[6.401]54.507[10.264]1.440[0.566]187.116[21.492]

0.711[0.541]152.300[40.329]

Enrollment rate for kindergartens and center-based childcare (%) 1334
Men’s high school enrollment rate (%)

1334

Women’s high school enrollment rate (%)

1334

Employment rate of women ages 25-44 (%)

414

Outcomes for placebo tests
Adult violent arrest rate (per 1,000 individuals)

1334

Adult pregnancy rate (per 1,000 women)

1334

Notes: Data for all variables, except for the female employment rate, are available for 46 provinces for
29 years (46 ⇥ 29 = 1334). The employment rate is taken from 9 waves of quinquennial census(46 ⇥ 9 = 414), and we focus on women ages 25-44. Numbers in square brackets are standard
deviations. See Table B.1 for definitions and data sources of each variable.

6

Results

To assess the long-term consequences of the kindergarten reform, we focus on risky behavior,including violent and nonviolent crime rates and the teenage pregnancy rate. In addition to theseprimary outcomes, we also examine the high school enrollment rate, the center-based childcare
enrollment rate, and the female employment rate as secondary outcomes because they shed lighton the underlying mechanisms for why the reform affected the main behavioral outcomes.

18

6.1

Crime and Pregnancy Rates

This section provides evidence for the effects of the kindergarten reform on juvenile crime andteenage pregnancy rates. We begin by graphically comparing the time trends of outcomes in
two groups of provinces; the first group includes strongly affected (i.e., treatment) provinces,and the second includes less affected (i.e., comparison) provinces. Through this exercise, we
illustrate how we identify the causal effects of the reform in an intuitive and transparent manner.
We then show the estimates from the event study model (see Equation 1) in which we control
for the pre-reform characteristics of provinces.
6.1.1

Graphical Evidence

In Figure 5, we compare the trends of adolescent behavioral outcomes between two groups
of provinces. One consists of provinces where the growth of the kindergarten enrollment rateduring the reform was above the median. For brevity, we refer to these as treatment provinces.
The other group consists of provinces with below-median growth, which are referred to ascomparison provinces. Because a juvenile offender is a person between 14 and 19 years of age
in Japan, we define the phase-in period according to when the treated cohorts fell in this age
range. The first treated cohort reached 14 years of age in 1974, while the last treated cohort
reached 19 years of age in 1985. Therefore, we define the phase-in period as beginning in 1974
and ending in 1985 (see Figure 4).
Panel A shows the trend in the juvenile arrest rate for violent crimes. In the pre-reformperiod, the rate was higher among the treatment provinces than among the comparison provinces.
However, the gap narrowed during the phase-in period and disappeared in the post-reform period.
We find similar patterns with non-violent crimes in Panel B. As shown in panel C, the rate of
teenage pregnancy was higher in treatment provinces in the pre-reform period, but the gap
reversed in the phase-in period and remained stable throughout the post-reform period.15
Our graphical evidence suggests that the kindergarten reform decreased juvenile arrests and
15One might wonder why the juvenile arrest rate temporarily rose during the late 1970s and early 1980s.
The literature offers possible explanations including deteriorating labor market conditions (Tsushima,
1996; Ohtake and Okamura, 2000), cohort crowding (Ichikawa and Nakamura, 1988), and increased
police activity (Yokoyama, 1989), but there appears to be no consensus on the mechanism.

19Arrestees per 1000 individuals

Figure 5: Variations in juvenile arrest and teenage pregnancy rates
Panel A. Violent arrest
Panel B. Non-violent arrest
22

4

20

Treatment Provinces

Treatment Provinces

18

3

16
14

2

12
1

Comparison Provinces
1970

1975

1980

Year

1985

Comparison Provinces

10
1990

1995

1970

1980

Year

1990

Cases per 1000 women

Panel C. Teenage pregnancy
12Treatment provinces:

Comparison Provinces

23 provinces where kindergarten growth10

rates during the reform are above median.

8Comparison provinces:

Treatment Provinces

23 provinces where kindergarten growth
rates during the reform are below median.

6
1970

1975

1980

Year

1985

1990

1995

Notes: This figure displays variations in juvenile behavioral outcomes separately for treatment andcomparison provinces. We define “treatment provinces” as provinces where the growth of thekindergarten enrollment rate during the reform exceeded the median among all provinces, while
comparison provinces are those with below-median growth. The two vertical dashed lines demarcate
the three periods defined in Figure 4: the pre-reform period (1967-1973), phase-in period (1974-1985),
and post-reform period (1986-1995).

20

teenage pregnancy, but we do not control for any observed provincial characteristics prior totreatment here. We address this concern in the following section using the event study model.
6.1.2

The Event Study Model

We estimate the causal effects of the kindergarten reform using the event study model (1) andpresent the estimates graphically in Figure 6 with standard errors clustered at the provincial
level. Panel A shows the estimates for the juvenile violent arrest rate. In the pre-reformperiod (1967-1973), most of our estimates are close to zero and statistically insignificant,
implying the absence of a pre-trend. In the phase-in period (1974-85), there is a downward
trend16. Finally, throughout the post-reform period (1986-1995), the estimates are significantly
negative, implying that the reform has reduced the juvenile violent arrest rate.
Panel B shows the estimates for the juvenile non-violent arrest rate. We find that theestimates are small and statistically insignificant in almost all years including the post-reformperiod. Although Figure 5 suggests that the reform may have reduced non-violent arrests, theresults are not robust once we control for the pre-reform provincial characteristics. Panel C
shows the estimates for the teenage pregnancy rate. We find no evidence for a pre-trend. In thephase-in period, the estimates exhibit a downward trend and are significantly negative in the last
few years of the phase-in period and the first few years of the post-reform period. The estimates
become insignificant later in the post-reform period.
Table 3 summarizes the estimation results by averaging the estimates over years during eachof the pre-reform, phase-in, and post-reform periods. In the pre-reform period, the estimates
are close to zero and insignificant for all outcomes, implying no evidence for a pre-trend. For
the juvenile violent arrest rate, the effect of a 10-percentage-point increase in the kindergarten
enrollment rate is -0.501 in the post-reform period and statistically significant at the 1% level.
For the non-violent arrest rate, the estimated effect in the post-reform period is negative at 0.542, but its large standard error leads to an insignificant result. For the teenage pregnancy rate,
16One might wonder why the estimated effects on arrest rates temporarily rose in the early 1980s (seePanels A and B of Figure 6). This is largely driven by a temporary increase in juvenile arrest rates inprovinces with a higher growth in the kindergarten enrollment rate (see also Figure 5 and the discussions
in Section 6.1.1). Section 7 discusses how adding time-varying confounders to the baseline model (1)may affect our estimates.

21

Figure 6: Effects of the kindergarten reform on juvenile arrest and teenage pregnancy rates

Notes: This figure shows the estimated effects of the kindergarten reform. Specifically, we plot theestimates for Û⌘ , the coefficients for the growth of the kindergarten enrollment rate during the reform, inthe event study model (see Equation 1). The shades indicate the 90% confidence bands. The estimatesindicate the effects of a 10-percentage-point increase in the kindergarten enrollment rate. Standard
errors are clustered at the provincial level. The vertical dashed lines at 1973 and 1985 demarcate theestimates into the three periods indicated in Figure 4: the pre-reform period (1967-1973), phase-in
period (1974-1985), and post-reform period (1986-1995).

the estimated effect in the phase-in period is -0.588 and statistically significant at the 1% level.
The estimate in the post-reform period is slightly larger at -0.631 and statistically significant at
the 10% level. Given that the reform increased kindergarten enrollment for the entire country by
21 percentage points, these estimates imply that the reform reduced the juvenile violent crime
rate by 1.052 and the teenage pregnancy rate by 1.325, which are 38% and 17% reductions fromthe pre-reform averages, respectively.17
Our estimates are difficult to compare with those of previous studies because criminal
17 The estimate for the violent crime rate is obtained by 0.501 ⇥ 21/10 = 1.052. Because the prereform average is 2.743, the reduction rate is 1.052/2.743 = 0.38. Similarly, the estimate for teenage
pregnancy is obtained by 0.631 ⇥ 21/10 = 1.325, and the reduction rate is 1.325/7.857 = 0.17.

22

outcomes are measured differently between studies. In particular, our measurement, the juvenile
violent crime rate, covers a shorter time period (six years from 14 to 19 years) and a more specific
type of crime than other studies. Similarly, fertility outcomes are measured from different age
ranges across studies, and therefore estimates are not directly comparable.
Table 3: Estimated effects of the kindergarten reform by period
Pre-reform Phase-in Post-reform
(1)
(2)
(3)
(A) Juvenile violent arrest-0.063(0.073)-0.179(0.137)-0.501(0.150)(B) Juvenile non-violent arrest-0.172(0.321)-0.045(0.441)-0.542(0.586)(C) Teenage pregnancy-0.173(0.189)-0.588(0.218)-0.631(0.344)

Notes: This table presents the estimated effects of the kindergarten reform during the pre-reform period(1967-1973), phase-in period (1974-1985), and post-reform period (1986-1995). See Figure 4 fordefinitions of the three periods. To calculate the estimates, we estimate the coefficient U⌘ in the event
study model (1) for each year, and then separately estimate its average over years during each of thethree periods. The estimates indicate the effects of a 10-percentage-point increase in the kindergarten
enrollment rate. Standard errors are in parentheses; they are clustered at the provincial level andobtained using the Delta method.

6.2

Secondary Outcomes

6.2.1

High School Enrollment

Next, we estimate the effects of the kindergarten reform on high-school enrollment rates forboys and girls separately. We study this outcome for two reasons. First, high school enrollment
is an important educational outcome in itself because high school is not a part of compulsory
education in Japan. Second, high school enrollment is a possible mediator of behavioral
outcomes such as juvenile arrests and teenage pregnancy. Lochner (2011) points out thereasons additional schooling can reduce juvenile crime. First, additional schooling can lead toincapacitation effects, as opportunities for crime and pregnancy are typically more limited inschools than on the street. Second, additional schooling can promote skills among children,
increasing the opportunity cost of engaging in risky behavior.
23

Table 4: Effects of the kindergarten reform on high school enrollment, ECEC enrollment, andfemale employment
Pre-reform Phase-in Post-reform
(1)
(2)
(3)
High school enrollment(A1) Men(A2) Women-0.334(0.291)-0.249(0.260)-0.042(0.285)-0.290(0.329)-0.271(0.528)-0.502(0.489)0.297(0.234)0.151(0.407)-0.458(0.313)4.423(0.571)-2.103(0.780)9.234(0.846)0.047(0.032)-0.715(0.903)0.152(0.826)ECEC enrollment(B1) Center-based childcare(B2) Center-based childcare and kindergartens
Female employment(C) Employment rate among women ages 25-44

Notes: This table presents the estimated effects of the kindergarten reform during the three periods: thepre-reform period, phase-in period, and post-reform period. The estimates indicate the effects of a
10-percentage-point increase in the kindergarten enrollment rate. We estimate the coefficient U⌘ in theevent study model (1) for each year, and then its average over years during each of the three periods. We
adjust the definitions of the three periods for each outcome as follows. The pre-reform period is definedfor rows (A1)-(A2) as 1968-72, for (B1)-(B2) as 1974-81, and for (C) as 1955. The phase-in period isdefined for rows (A1)-(A2) as 1974-85, for (B1)-(B2) as 1964-70, and for (C) as 1965 and 1970. The
post-reform period is defined for rows (A1)-(A2) as 1982-96, for (B1)-(B2) as 1971-85, and for (C) as
1975-95. Standard errors are in parentheses; they are clustered at the provincial level and obtainedusing the Delta method.

Results are reported in rows (A1)-(A2) of Table 4. The estimated effects of a 10-percentagepoint increase in the kindergarten enrollment rate caused by the reform are -0.271 percentage
points for boys and -0.502 percentage points for girls and are statistically insignificant, suggestingthat the kindergarten reform did not increase high school enrollment. This may be because there
was little room for improvement as the high school enrollment rates were already high. These
rates were 91% for boys and 93% for girls during the analysis period, as reported in Table 2. This
null result suggests that increased schooling is unlikely to be the primary reason kindergarten
reform reduced violent crime among juveniles and teen pregnancy.

24

6.2.2

Enrollment for Center-Based Childcare

We also examine how the kindergarten reform affected other types of childcare. This helps us
interpret the estimated effects on juvenile outcomes because the effects on a juvenile outcome
depend on both an observed outcome with the reform and a counterfactual outcome without thereform. In other words, estimating the effects of the reform on other childcare choices allows us
to understand the counterfactual mode of care and subsequent counterfactual juvenile outcomesin the absence of the reform.
Specifically, we estimate the effects on the enrollment rate for center-based childcare otherthan kindergartens. As detailed in Section 3.1, these are distinct programs in the Japanese
ECEC system and are likely to be imperfect substitutes. If the reform simply moved children
from center-based childcare to kindergartens, the effects are from an intensive margin (i.e., froma full-day center-based childcare to a half-day kindergarten). If the reform had little effect on
center-based childcare, the effects arise from an extensive margin (i.e., from informal care tokindergartens).
We find that a 10-percentage-point increase in the kindergarten enrollment rate during thereform decreased the enrollment rate of center-based childcare by 2 percentage points, while it
increased the overall enrollment rate of ECEC (i.e., kindergartens and center-based childcare)by 9 percentage points in the post-reform period (see rows B1-B2 in Table 4). Note that during
the analysis period, the enrollment rate for center-based childcare for 4-year-olds was 20% andthat for overall ECEC (i.e., kindergartens and center-based childcare) was 56% as reported inTable 2.
These results imply that the kindergarten reform did not substantially crowd out enrollment
in center-based childcare. We consider these results to be intuitive because, as described in
Section 3.1, kindergartens and center-based childcare differ in how they serve families withpreschool-aged children. These results also suggest that the observed effects on violent arrest
and teenage pregnancy appear to be the consequences of a change at the extensive margin (frominformal care to kindergartens) rather than at the intensive margin. Note that our results here
are based on estimates averaged across all provinces and may not be applicable to all provinces
individually. We further examine possible heterogeneity in substitution in Section 6.3.
25

6.2.3

Female Employment

Although kindergartens take children for only four hours a day, some women may choose to work
part-time, which may eventually influence child development. For example, women working
increases household income, which is likely to lead to better child outcomes. However, mothers
working could also harm child development if stress and fatigue at work cause deterioration inmother-child relationships (Baker, Gruber and Milligan, 2008).
To address this issue, we estimate the effects of the kindergarten reform on the employment
rate among women ages 25-44 using data from the quinquennial census from 1955 to 1995.
The ideal outcome to examine would be the maternal employment rate, but it is not available forthe analysis period. Furthermore, conditioning on being a mother may not be a valid statisticalanalysis because fertility may also be affected by the reform. The female employment rate was54.507% during the analysis period (see Table 2). Also note that 63% of women ages 25-44 were
married and had at least one child in 1960. A 10-percentage-point increase in the kindergarten
enrollment rate is associated with a 0.15-percentage-point higher female employment rate in
the post-reform period (see row C of Table 4). Although positive, the estimated effect is smalland statistically insignificant. The null effect on the female labor supply is unsurprising because
kindergartens only offer half-day services and therefore have a limited scope to affect parental
time allocation.

6.3

Heterogeneity of the Treatment Effects

Finally, we examine the possible heterogeneity of the treatment effects of the kindergarten reform. Previous studies have shown that children in disadvantaged families tend to benefit morefrom accessing early childhood education and care (see, e.g., Havnes and Mogstad (2015), Kottelenberg and Lehrer (2017), Cornelissen et al. (2018), Felfe and Lalive (2018), and Yamaguchi,
Asai and Kambayashi (2018b)). Unfortunately, we cannot examine heterogeneous effects interms of the socioeconomic status of individual households because our data are aggregatedat the provincial level. Instead, we group provinces in terms of the share of women with low
education and examine treatment effects separately for each group. We consider the share ofwomen with low (i.e., less than high school) education in 1960 as a proxy for the share of26

disadvantaged families within each province.
Table 5 reports how the estimated effects of treatment differ between the two groups ofprovinces with different levels of education of women. In this table, we refer to provinceswith a below-median share of low-education women as high-education provinces and the rest
as low-education provinces. The results of the estimations in the post-reform period suggestthat the kindergarten reform led to reductions in violent juvenile arrests and teenage pregnancy
only in high-education provinces (rows A1 and C1). On the other hand, corresponding postreform estimates for low-education provinces are close to zero (rows A2 and C2). These results
imply that the estimated effects in the baseline results (see Table 3) are largely driven by thehigh-education provinces.
One possible explanation for the null effect in low-education provinces is that the qualityof the counterfactual care mode was similar to that of kindergartens. That is, while the higheducation provinces include urbanized regions where more mothers were housewives in nuclear
families, the low-education provinces mainly consist of rural regions where many mothers
worked using center-based childcare. Specifically, the female employment rate in low-education
provinces was higher than that in high-education provinces by about 14 percentage points in
1960. As pointed out by a municipal survey in Okada (1982), some kindergarten slots createdby the reform may have crowded out center-based childcare in rural low-education provinces.
Our estimates in Table 6 do in fact indicate a substitution between kindergartens andcenter-based childcare in the low-education provinces. Among the low-education provinces,a 10-percentage-point increase in the growth of the kindergarten enrollment rate led to a 7.5percentage-point decrease in center-based childcare enrollment (row A2). Consequently, thereform resulted in only a 4.8-percentage-point increase in the overall ECEC enrollment rate(row B2). On the other hand, counterfactual care in urbanized high-education provinces seems
to be informal care provided by mothers because we do not observe a sizable crowding out ofcenter-based child care in these provinces (row A1).
In summary, the estimated heterogeneity of the treatment effect may be explained by the factthat the main counterfactual form of care in the high-education provinces is parental care, whilethat in the low-education provinces includes a substantial portion of center-based childcare.

27

Table 5: Heterogeneity of treatment effects on adolescent outcomesPre-reform Phase-in Post-reform
(1)
(2)
(3)
Juvenile violent arrests(A1) High-education provinces(A2) Low-education provinces
Difference (A1-A2)-0.057(0.125)0.098(0.172)-0.408(0.113)0.146(0.178)-0.661(0.193)0.147(0.153)-0.155(0.210)-0.554(0.209)-0.809(0.244)0.085(0.663)0.453(0.503)-0.727(0.413)0.272(0.668)-0.523(0.733)-0.586(0.703)-0.368(0.823)-1.000(0.777)0.063(1.005)-0.307(0.192)-0.285(0.273)-0.858(0.344)-0.256(0.366)-1.387(0.597)0.162(0.580)-0.023(0.331)-0.602(0.497)-1.549(0.823)Juvenile non-violent arrests(B1) High-education provinces(B2) Low-education provinces
Difference (B1-B2)
Teenage pregnancy(C1) High-education provinces(C2) Low-education provinces
Difference (C1-C2)

Notes: This table presents the averaged estimates (Û⌘ , ⌘ 2 [1967, 1995]) of the model (1) separately for
two groups of provinces: high-education provinces and low-education provinces. We define
high-education provinces as those with a below-median share of women with less than high school
education in 1960, and the rest as low-education provinces. The sample size for both subgroups is 23.
Estimates indicate the effects of a 10-percentage-point increase in the kindergarten enrollment rate,setting the year 1973 as a reference year (⌘ = 1973). We average the estimates over the three periods
described in Figure 4: the pre-reform period (1967-1972), phase-in period (1974-1985), andpost-reform period (1986-1995). Standard errors are in parentheses; they are clustered at the provincial
level and obtained using the Delta method.

Note also that average mothers in high-education provinces were still undereducated in the
1960s from the current perspective. Specifically, 67% of women ages 25-44 in high-education
provinces and 79% of those in low-education provinces had less than high school education,according to the 1960 census. Hence, it is plausible that kindergartens provided better carethan parental care to households in the high-education provinces during and after the reform

28

Table 6: Heterogeneity of treatment effects on center-based ECEC enrollment
Pre-reform Phase-in Post-reform
(1)
(2)
(3)
Center-based childcare(A1) High-education provinces(A2) Low-education provinces
Difference (A1-A2)

0.310(0.549)0.329(0.345)-0.514(1.052)-3.109(0.700)-1.880(2.239)-7.486(1.377)-0.019(0.641)

2.595(1.250)5.606(2.600)0.198(0.695)-0.717(0.731)6.974(1.116)4.365(0.652)8.921(1.678)4.865(1.446)0.914(0.997)2.608(1.279)4.056(2.192)Center-based childcare and Kindergartens(B1) High-education provinces(B2) Low-education provinces
Difference (B1-B2)

Notes: This table presents the estimates (Û⌘ , ⌘ 2 [1957, 1985]) of the event study model (1) separately
for two groups of provinces: high-education provinces and low-education provinces. We average theestimates over the following three periods: the pre-reform period (1957-1962), reform period(1964-1970), and post-reform period (1971-1985). High-education provinces are those with abelow-median share of women with less than high school education in 1960, and the other provinces arereferred to as low-education provinces. The sample size for both subgroups is 23. Estimates indicate
the effects of a 10-percentage-point increase in the kindergarten enrollment rate. Standard errors are inparentheses; they are clustered at the provincial level and obtained using the Delta method.

period. Admittedly, we cannot exclude the possibility that other factors correlated with maternal
education at the provincial level drive the results in this section.

7

Specification Checks

We perform a battery of specification checks for the preferred event study model. First, we
conduct a set of placebo tests in which we take as outcomes the arrest and pregnancy rates of older
cohorts that were not directly affected by the kindergarten reform. Second, we estimate treatment
effects using alternative model specifications to address the following concerns: inter-provincial
migration, endogeneity in kindergarten enrollment decisions, time-varying confounders, andthe choice of control variables.
29

7.1

Placebo Tests

We do not find a significant difference in the pre-intervention trends of the outcome variables
between provinces, but our estimates may still be biased if there exists a confounding factor thatis correlated with the treatment variable and outcome trends in the phase-in and post-reformperiods. An example of such a confounder is a labor demand shock. Previous studies havefound that deteriorating labor market conditions are strongly associated with the crime rate
(Chalfin and McCrary, 2017). If a labor demand shock is also correlated with the growth of
the kindergarten enrollment rate during the reform, our estimates may reflect differential timetrends in the outcomes caused by the labor demand shock, rather than a true policy effect. Such a
confounder may also arise if alternative policy variations coincide with the kindergarten reform.
Although we are not aware of any institutional changes that are likely to affect juvenile crimeand / or teen pregnancy rates (see Section 4.3 for a discussion of this topic), there could be an
unobserved provincial policy change that affects criminal and/or fertility behavior generally. Ifsuch a policy change is correlated with the treatment variable, the parallel trend assumption isviolated.
To address these concerns, we perform placebo tests using outcomes from cohorts older than
the reform cohort. The older cohorts are not supposed to be affected by the kindergarten reformas they had passed preschool age before the reform, but they are likely to be affected by thekind of unobserved labor demand shocks and policy changes mentioned above. Therefore, we
may detect the presence of a confounder that biases our estimates if the reform is significantly
associated with the placebo outcomes of older cohorts. In practice, we use the adult arrest rate
for violent crime and adult pregnancy rate as placebo outcomes. Strictly speaking, the placebo
outcomes during the post-reform period include the outcomes of the affected cohort, but these
are negligibly small compared to the entire adult population. Even if this affects the placebo
tests to some degree, it only increases the chance of a failing result. We admit that the placebo
tests do not rule out the presence of a confounder that affects only teenagers, but passing theplacebo tests would give us more confidence in our main results.
Figure 7 presents the results of the placebo tests. The average adult arrest rate for violent
crimes was 0.710 per 1,000 adults and the adult pregnancy rate was 126 per 1,000 women (see30Table 2). For both the adult violent crime and pregnancy rates, we find insignificant effects
throughout the period of analysis. The magnitude of the estimated effects during the post-reformperiod is less than 1% of the averages for both outcomes: about -0.007 for adult arrests and-0.796 for adult pregnancy. Null results in the falsification tests give us added confidence that
our main results are driven by the kindergarten reform and not by unobserved confounders.
Figure 7: Placebo tests: estimated effects on older (unaffected) cohorts

Notes: This figure shows the estimated effects of the kindergarten reform on older cohorts that are notdirectly affected by it. Specifically, we plot the estimates for Û⌘ , the coefficients for the growth of thekindergarten enrollment rate during the reform, in the event study model (see Equation (1)). The shades
indicate the 90% confidence bands. Standard errors are clustered at the provincial level. The twovertical dashed lines at 1973 and 1985 demarcate the three periods described in Figure 4: thepre-reform period (1967-1973), phase-in period (1974-1985), and post-reform period (1986-1995).

31

7.2

Other Threats to Identification

This section addresses four remaining concerns about our identification strategy: (1) interprovincial migration, (2) endogeneity in kindergarten enrollment decisions, (3) influence oftime-varying confounders, and (4) choice of control variables. We discuss each of these inorder and present all results at the end of this section.
Inter-Provincial Migration

First, inter-provincial migration is a potential source of an en-

dogeneity bias. Rapid economic growth during 1955-1973 in Japan attracted a substantial
population from rural to urban regions (Fielding, 2017). If crime-prone youth moved disproportionately from rural to urban regions, the crime-reducing effects may be biased downward
because the kindergarten enrollment rate increased faster in the metropolitan area during thekindergarten reform (see Table 1). Nevertheless, inter-provincial migration was relatively rareamong teenagers and only 9% of junior high school graduates in 1970 moved to another province
after finishing compulsory education at age 15. Although we suspect that inter-provincial migration does not affect our estimates substantially, we address possible biases by removing thelargest destination provinces from our data and re-estimating the event study model (1) with thesame set of covariates used in Section 6.1.2.18 Specifically, we exclude observations for Tokyo
and Osaka because they are the two most popular destinations for individuals moving out of
their home province to take a job upon graduating junior high school. According to the 1970
School Basic Survey, 37% of job seekers moved to one of these two provinces.
Endogenous Kindergarten Enrollment

Second, endogenous kindergarten enrollment deci-

sions can bias our estimates. Parents who are enthusiastic about education are more likely toinvest in their children not only by enrolling them in kindergartens, but also by spending theirtime and money. As a result, their children are less likely to be arrested in adolescence, even if
kindergarten has no effect on the juvenile arrest and teenage pregnancy rates. In other words,
unobserved parental characteristics, such as enthusiasm for education, can affect kindergarten
enrollment and behavioral outcomes during adolescence. To address a potential endogeneity
18 Kondo and Shigeoka (2013) also use panel data for Japanese provinces and adopt a similar approach
to examining the potential influences of inter-provincial migrations on their estimates.

32

bias, we instrument the kindergarten enrollment rate by measures of the supply of kindergarten
education, including the number of kindergartens, kindergarten teachers, kindergarten classrooms, and kindergarten slots per child in a province. These supply-side variables are likely to
be uncorrelated with unobserved parental characteristics.
Time-Varying Confounders Third, time-varying confounding factors during and after thekindergarten reform may bias our estimates. In our preferred specification (1), we control for
pre-reform provincial characteristics but exclude post-reform characteristics because the latter
may be affected by the kindergarten reform. Nevertheless, one might be concerned about biases
arising from not controlling for post-reform provincial characteristics correlated with both thetreatment and outcome variables. To address this concern, we estimate an alternative modelthat includes a set of time-varying control variables in addition to the pre-reform provincial
characteristics. These variables include lagged real provincial GDP per capita, real child welfare
spending per capita, real fiscal-equalization grants per capita, and police officers per capita as
proxies for local economic conditions, child welfare policies, and local police activities.
Alternative Set of Control Variables Fourth and finally, our model may fail to include
relevant pre-reform control variables. To overcome this limitation, we substantially expand theset of pre-reform regional characteristics as control variables and apply the post double selection
lasso proposed by Belloni, Chernozhukov and Hansen (2014). Specifically, we estimate thecross-sectional first-difference DID model.8g = .8g

.8g = Ug /8 + V0 -8 + Y8g at each C = g, where.8)0 and )0 is a pre-reform reference year. In this model, the components of -8

are selected by the lasso-based procedure that selects the most relevant control variables topredict .8g and /8 at each C = g from a set of high-dimensional covariates. Ug is the parameterof interest. For the candidates for control variables -8 , we use 56 pre-reform covariates (i.e.,levels and differences of 28 covariates around C = )0 ) and their quadratic terms, resulting in 112
covariates. Appendix B lists these covariates.
Estimation Results

Figure 8 presents the results of the robustness checks. The estimateslabeled “without Tokyo and Osaka”, “supply-side IV”, “ time-varying covariates” and “double
33

selection” are based on the model specifications that address the above four concerns. For
comparison, we also show estimates from the preferred baseline specification. We find thatthe primary findings of the baseline analysis are robust to the alternative model specifications
and estimation methods. For all the outcomes, pre-reform estimates do not differ significantly
from zero, suggesting that our results are not driven by pre-existing differential trends. For thephase-in and post-reform periods, the estimated effects on the arrest rate for violent crimes andthe teenage pregnancy rate are largely negative and statistically significant, whereas those on the
non-violent arrest rate are insignificant. In general, the results of the alternative specifications
are in line with the baseline results in Section 6.1.2.
Figure 8: Estimated effects of the reform under alternative specifications
Arrest for violent crime

Arrest for non−violent crime

0.5

2

1
0.0
0

−1

−0.5

−2

1970

1975

1980

1985

1990

1995

1970

1975

1980

1985

1990

1995

Teenage pregnancy

0

Estimation model/method
Baseline
Without Tokyo and Osaka
Supply−side IV
Time−varying covariates
Double selection

−1

−2
1970

1975

1980

1985

1990

1995

Notes: This figure displays the estimates with 90% confidence intervals regarding the effects of thekindergarten reform under alternative specifications described in Section 7.2. Except for the double
selection estimates which are obtained by the cross-sectional first-difference model, standard errors are
clustered at the provincial level. Two vertical lines at 1973 and 1985 correspond to the three periods
described in Figure 4: the pre-reform period (1967-1973), phase-in period (1974-1985), andpost-reform period (1986-1995). The first-stage -statistic for the kindergarten-supply IV estimation is40.790, based on a cross-sectional regression of the treatment variable on the instruments and baseline
covariates.

34

8Discussion

We show that the kindergarten reform decreased the juvenile arrest rate for violent crimes andthe teenage pregnancy rate, but why did it have these effects? Our result in Section 6.2.1 does
not support an explanation based on the incapacitation effects of additional schooling because
the reform did not increase the high school enrollment rate. This finding is largely consistent
with previous evidence from targeted programs. Heckman et al. (2010) find that the PPP did
not increase the male high school graduation rate but nevertheless decreased the male crimerate. Carneiro and Ginja (2014) report similar results for Head Start.
A more plausible explanation for why early childhood education reduces adolescent risky
behavior is improvement in children’s non-cognitive skills. In criminology and psychology,
it is well documented that childhood externalizing behavior predicts later antisocial behavior
and arrests for violent crimes (Farrington, 1989; Moffitt, 1993). Heckman, Pinto and Savelyev(2013) show that the PPP alleviates externalizing behavior among children and that these effects
account for most of the crime-reducing benefits of this program. Cultivating noncognitive
skills is also likely to reduce teenage pregnancy, according to developmental psychologists.
Arnold and Coyne (2020) argue that early childhood education decreases behavioral problems
in schools and increases future aspirations, which potentially reduces the associated risk of
teenage pregnancy.
The kindergarten curriculum in Japan is comparable with the HighScope curriculum, as bothare based on a child-centered rather than teacher-centered approach. Schweinhart and Weikart(1997) find that programs based on a child-centered approach lead to fewer crimes at age 23
than a program based on a teacher-centered approach in their randomized study in Ypsilanti,
Michigan. A child-centered approach is generally expected to foster non-cognitive skills rather
than academic skills. Although we are unable to evaluate the effects of the kindergarten reformon children’s behavior and non-cognitive skills because of a lack of data, there is evidence fromJapan that early childhood education reduces children’s externalizing behavior. Yamaguchi,
Asai and Kambayashi (2018b) show that center-based childcare in Japan reduces symptoms
of attention deficit hyperactivity disorder (ADHD) and aggressive behavior among children of
mothers with less than high school education. Given that about 72% of young women 2535

44 years of age had less than high school education before the kindergarten reform, children
affected by the kindergarten reform were likely to have benefited from better quality care.
Although in the opposite direction, studies of Quebec’s universal childcare program also
demonstrate that early childhood education affects the crime rate in adulthood through themediation of behavior and non-cognitive skills in early childhood. Baker, Gruber and Milligan(2008) find that the Quebec childcare reform increased the maternal labor supply, parental stress,
and low-quality parenting styles, causing deficits in non-cognitive outcomes among children.
Baker, Gruber and Milligan (2019) show that negative effects on non-cognitive outcomes
persisted until adolescence and that cohorts with greater access to childcare had a higher crime
rate later in life.
In sum, we speculate that the kindergarten reform in Japan improved children’s non-cognitive
skills and reduced externalizing behavior, which eventually resulted in reducing the juvenile
arrest and teenage pregnancy rate. Improved non-cognitive skills may have raised people’s
earnings, and hence the opportunity cost of engaging in risky behavior. Our results do notsupport the view that the incapacitation / incarceration effect of additional schooling plays asignificant role in accounting for the effects of the kindergarten reform on criminal and fertility
behavior in adolescence.

9

Conclusion

Social benefits associated with reducing risky behavior in adolescence can justify large public
expenditures on early childhood education. Evidence from a small number of targeted interventions for disadvantaged children has demonstrated their effectiveness, but little is known about
the efficacy of large-scale universal early childhood education programs, particularly outside ofNorth America. We contribute to the literature by providing new evidence from Japan, where
the institutions significantly differ from those in North America.
Our estimates show that the kindergarten reform in Japan has significantly reduced violent
arrests and pregnancy among teenagers. Given that Japan had low arrest and teenage pregnancy
rates, our findings demonstrate the potential of a universal early childhood program outside of36

North America to produce long-lasting benefits for children and society at large.
An important limitation of our study is a lack of non-cognitive skill measurement. Our
result shows that the kindergarten reform did not affect the high-school enrollment rate, which
implies that the hypothesis of an "incarceration" effect can be rejected. We argue that improved
non-cognitive skills are a likely channel through which early childhood education prevents
adolescent risky behavior, but we do not observe children’s non-cognitive skills.
Another limitation is that we do not have individual-level data. As our provincial panel data
provide administrative records for crime and pregnancy, they are likely to be precise, and wehave very little concern about under-reporting. However, our aggregate data prevented us from
implementing a detailed subgroup analysis at the individual level to uncover the heterogeneity ofthe treatment effect. The question of how the effects on risky teenage behavior vary with gender,family background, and other individual characteristics remains. We leave these important tasks
to future research.

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43

A

Kindergarten Curriculum Standards and Regulations

Kindergarten regulations impose strict quality standards for education in kindergartens in Japan.
Kindergartens are part of the formal education system. The School Education Act (1947)
stipulates the duties of kindergarten teachers, as well as the roles of kindergartens as a formal
provider of pre-primary education to children over the age of 3. The Ministry of Education
gradually strengthened the regulation of kindergartens after WWII by introducing national
curriculum standards in 1948, imposing license requirements on kindergarten teachers in 1949,and specifying classroom regulations in 1952. In the following, we describe the national
curriculum standards for kindergartens that play a central role among those regulations.
Ever since the post-WWII educational reforms during the American occupation of Japan(1945-52), national kindergarten curriculum standards have emphasized the importance of children’s hands-on experiences and learning rather than teacher-centered instruction. In particular,
the Ministry of Education developed new preschool curriculum guidelines in 1947 with theadvice of Helen Heffernan as mentioned in Section 3.1. These guidelines were the foundationof the National Curriculum Standards for Kindergartens, which has been implemented since1956 with minor revisions. Both the original guidelines and the national curriculum standards
underscore the importance of centering kindergarten activities around children’s interests andneeds – physical, cognitive, psychological, and social – to promote their health and personality
skills. The national curriculum standards require 4 hours of instruction and care per day on
every weekday for at least 39 weeks per year. All kindergartens in Japan, regardless of whether
they are public or private, must adhere to these standards.
Understanding the relative merits of various curriculum models may be relevant for interpreting the results of early childhood interventions. While there are various curriculum
approaches for early childhood education, they can be broadly classified into two categories,
teacher-centered approaches and child-centered approaches, depending on the degree of initiative expected of children. In teacher-centered approaches, teachers play a primary role inorganizing small groups of children to teach subjects with question-and-answer lessons in awell-planned sequence. Learning priorities in these approaches are often given to academic
skills that can be assessed by intelligence and achievement tests. In child-centered approaches,
44

children have choices of learning activities based on their interests and needs, while teachers facilitate key experiences in children’s development such as social relations, literacy, and creative
representation. Child-centered approaches emphasize the development of social skills rather
than academic skills.
The following five development goals encapsulate the educational content of the kindergarten
curriculum: (1) physical development and health, (2) social relations, (3) environment andnature, (4) language and literacy, and (5) creative representations. The first national curriculum
published in 1956 had six developmental goals, defining music and drawing as two separate
goals. A revision of the national curriculum standards in 1988 integrated them into a single goalas creative representation. All of these goals are key components of the HighScope curriculum
and the Head Start framework.
Kindergartens are also responsible for providing basic medical services to children in kindergartens. The School Health Law requires that a kindergarten employ a school physician. School
physicians typically work part-time, and their main duties are to supervise school-based medical
checks and to provide various health services to children and teachers. School physicians also
provide first-aid treatment to students at the request of school heads.

B

Details on Data

45

Variable nameMain outcomes
Juvenile violent arrest rate
Juvenile non-violent arrest rate
Teenage pregnancy rate

Table B.1: Definitions and data sources: main variables

46

Definition

SourceArrests per 1000 population ages 14-19 for violent crimes
Arrests per 1000 population ages 14-19 for non-violent crimes
Sum of abortion cases and childbirths per 1000 women ages 15-19(A), (C)(A), (C)(A), (D)

Additional outcomes
Center-base childcare enrollment rate at age 4
Overall center-based ECEC enrollment rate at age 4
Male high school enrollment rate
Female high school enrollment rate
Female employment rate
Adult violent arrest rate
Adult pregnancy rate

Enrollment rate in center-based childcare at age 4 divided by cohort size
Sum of kindergarten enrollment and childcare enrollment at age 4 divided by cohort size
Proportion of men enrolled in high schools at age 15 among those attended Grade 9
Proportion of women enrolled in high schools at age 15 among those attended Grade 9
Proportion of women ages 25-44 who are employed
Arrests per 1000 adults for violent crimes
Sum of abortion cases and childbirths per 1000 women ages 20-29(A), (B)(A), (B)
(A)
(A)
(F)
(A), (C)(A), (D)Treatment variables
Variation in kindergarten enrollment during the reform
Variation in overall center-based childcare enrollment during the reform
Kindergarten enrollment among individuals ages 14-19

Variation in kindergarten enrollment rate at age 4 during 1963-1971
Variation in enrollment rates in kindergartens and nurseries at age 4 during 1963-1971
Kindergarten enrollment rate at age 4 among individuals ages 14-19(A)(A), (B)(A)

Instrumental variables
Variation in kindergartens during the reform
Variation in kindergarten slots during the reform
Variation in kindergartens teachers during the reform
Variation in kindergartens classrooms during the reform

Variation in kindergartens per children ages 3-5 during 1963-1971
Variations in kindergarten teachers per children ages 3-5 during 1963-1971
Variation in kindergarten slots per children ages 3-5 during 1963-1971
Variation in kindergarten classrooms per children ages 3-5 during 1963-1971

Sources: (A) School Basic Survey, (B) Survey of Social Welfare Institutions, (C) Crime Statistics, (D) Vital Statistics

(A)
(A)
(A)
(A)

Variable name
Baseline controls
Kindergarten enrollment rate
Real provincial GDP per capita
Fiscal-equalization grants per capita
Share of low-educated women
Female employment rate
Child population ratio

Definition

Table B.2: Definitions and data sources: control variables

Source47

Proportion of children enrolled in kindergarten at age 4
Real Gross Provincial Product per capita (in 1980 JPY)
Real fiscal-equalization grants allocated to provinces divided by the provincial population
Proportion of women ages 25-44 without a high school degree
Proportion of employed among the population of women ages 25-44
Proportion of children in provincial population(A)(H)(H),(I)
(F)
(F)
(E)

Additional controls
Population
Population density
Monthly earnings
Male employment rate
Unemployment rate
Share of workers in secondary industries
Share of workers in third industries
Share of high school educated womenChildcare enrollment rate
Kindergartens per capita
Kindergarten teachers per capita
Elementary school teachers per student
Junior high school teachers per student
Provincial spending on child welfare
Provincial spending on education
Provincial spending on welfare
Provincial spending on civil construction
Provincial spending on public health
Provincial spending on kindergartens
Provincial spending on elementary schools
Provincial spending on junior high schools
Total provincial spending

Provincial population
Number of individuals per square kilometers
Average real monthly salary among workers in establishments with more than 30 employees
Proportion of employed individuals among the population of men
Number of unemployed individuals among the labor force
Proportion of workers in secondary industries among the population of workers
Proportion of workers in third industries among the population of workers
Proportion of women with a high school degree
Enrollment rate in nurseries at age 4
Number of kindergartens per child ages 3-5
Number of kindergarten teachers per child ages 3-5
Number of elementary school teachers per elementary school student
Number of junior high school teachers per junior high school student
Per capita real provincial expenditure on child welfare services
Per capita real provincial expenditure on education
Per capita real provincial expenditure on welfare services
Per capita real provincial expenditure on civil construction
Per capita real provincial expenditure on public health services
Per capita real provincial expenditure on kindergartens
Per capita real provincial expenditure on elementary schools
Per capita real provincial expenditure on junior high schools
Per capita real provincial expenditure

(F)
(E)
(J)
(F)
(F)
(F)
(F)
(F)
(A), (B)
(A)
(A)
(A)
(A)
(H), (I)(H), (I)(H), (I)(H), (I)(H), (I)(H), (I)(H), (I)(H), (I)(H), (I)Time-varying controls
Lagged real provincial GDP per capita
Fiscal-equalization grants per capita
Provincial spending on child welfare
Police officers per capita

Lagged real Gross Provincial Product per capita (in 1980 JPY)
Real fiscal-equalization grants allocated to provinces divided by the provincial population
Per capita real provincial expenditure on child welfare services
Number of police officers divided by provincial population(H)(H),(I)(H), (I)(C)

Sources: (A) School Basic Survey, (B) Survey of Social Welfare Institutions, (C) Crime Statistics, (D) Vital Statistics, (E) Population Estimates, (F) Census, (H)Province SNA (in 68SNA format), (I) Annual Local Public Finance Statistics, (J) Monthly Labor Survey

Figure B.1: Kindergarten enrollment rate before and after the reform
Ibaraki
Kochi
Kagoshima
NaganoMiyazaki
Iwate
Akita
Fukushima
Tottori
Oita
Hokkaido
Kumamoto
Miyagi
Gifu
NiigataNagasaki
AomoriMie
ToyamaSaga
Yamagata
Shiga
Yamanashi
Tochigi
Ehime
Chiba
Ishikawa
Shimane
Saitama
Fukuoka
Gunma
Fukui
Okayama
Hyogo
Wakayama
Yamaguchi
Aichi
Tokushima
Hiroshima
Nara
Kanagawa
Osaka
Kyoto
ShizuokaTokyo
Kagawa

1963
1971

0

10

20
30
40
50
Enrollment rate (percent)6070

Notes: This figure displays provincial kindergarten enrollment rates in 1963 and 1971. Provinces are
sorted by the enrollment rate in 1963.

C

Additional Results

C.1

Estimation without Covariates

The empirical models presented in Section 4.2 include a vector of covariates -8 that consists ofthe pre-reform characteristics of provinces in Table 1. To the extent that these covariates capture
pre-existing differences across provinces, we expect them to reduce potential noise and biases
in our baseline results presented in Section 6.1.2. To understand how the covariates affect out
baseline results, we show estimates without the covariates and compare them with our baseline48

Figure B.2: Kindergarten enrollment rate at age 4, 1955-1980
50
Enrollment rate at age 4

40

30
Projection based on 1955−1963

20

10

1955

1960

1965

1970

1975

1980

Year
Notes: This figure shows variations in the kindergarten enrollment rate at age 4, together with aprojection line obtained from a simple regression using the pre-reform data for 1955-63. The
gray-colored area corresponds to years during the kindergarten reform (1964-70).

results.
Table C.1 reports estimates based on the model (1) with and without the covariates. Estimates
without covariates exhibit greater effects on juvenile violent arrests and teenage pregnancy. At
the same time, we obtain substantially smaller standard errors when controlling the covariates.
These results suggest that the pre-reform covariates in the baseline model play an important role
in reducing noises and biases in our estimation.

49

Table C.1: Estimates of juvenile arrests and teenage pregnancy with and without covariates
Pre-reform Phase-in Post-reform
(1)
(2)
(3)
Juvenile violent arrest(A1) Baseline(A2) Without covariates-0.063(0.073)-0.050(0.057)-0.179(0.137)-0.226(0.135)-0.501(0.150)-0.586(0.308)-0.172(0.321)
0.236(0.313)-0.045(0.441)-0.222(0.365)-0.542(0.586)-0.477(0.415)-0.173(0.189)0.116(0.209)-0.588(0.218)-0.936(0.307)-0.631(0.344)-1.169(0.424)

Juvenile non-violent arrest(B1) Baseline(B2) Without covariates
Teenage pregnancy(C1) Baseline(C2) Without covariates

Notes: This table presents the estimated effects of the kindergarten reform obtained from the event
study model (1) and the model without covariates. Specifically, we estimate the coefficient U⌘ in theevent study model (1) for each year, and then take the average over the years comprising each of thethree periods described in Figure 4: the pre-reform period (1967-1973), phase-in period (1974-1985),
and post-reform period (1986-1995). We repeat the same procedure for a model without covariates.
Standard errors are in parentheses; they are clustered at the provincial level and obtained by the Deltamethod.

50

C.2

Fixed-Effect Regression

As a robustness check, we also estimate a more conventional fixed effects regression model:.8C = W⇢=A>;;8C + X0 -8C + c8 + `C + Y8C .

(C.1)

Here, the treatment variable ⇢=A>;;8C is the kindergarten enrollment rate in province 8 in year C,
and hence is time-varying. The rest of the parameters are defined similarly to the event study
model (1) while the parameter (W) is time-invariant in the fixed effects model (C.1).
Unlike the event study model (1), the fixed effect model (C.1) restricts the causal effects tobeing time-invariant. The recent econometric literature points out that this restriction can leadto biased estimates. In addition, the fixed effect model does not allow us to test for the existenceof a pre-trend.
Table C.2 reports the estimation results for a conventional fixed-effects regression model(C.1). Estimates show that both juvenile violent arrests and teenage pregnancy are negatively
associated with the kindergarten enrollment rate, but non-violent arrests are not significantly
correlated with the enrollment rate, conditional on the fixed effects and covariates. These
results align well with the findings from the baseline model shown in Figure 6 and Table 3. Thisestimate implies that a 10-percentage-point increase in the kindergarten enrollment rate reduces
the juvenile arrest rate for violent crimes by 0.280 individuals per thousand ages 14-19 and theteenage pregnancy rate by 0.491 cases per 1000 women ages 15-19.
Table C.2: Results of two-way fixed effects regressions
Fixed-effects regression(1)(A) Juvenile violent arrest-0.280(0.099)(B) Juvenile non-violent arrest

0.376(0.350)(C) Teenage pregnancy-0.491(0.264)

Notes: This table presents the estimates, Ŵ, of the two-way fixed effects model (C.1). These estimatesindicate the effects of a 10-percentage-point increase in the kindergarten enrollment rate at age 4.
Standard errors in parentheses are clustered at the provincial level.

51