Zhang Dandan: "very strong correlation" between left-behind childhood and criminality in adulthood
Zhang Dandan: "very strong correlation" between left-behind childhood and criminality in adulthood
Peking University scholar highlights long-term social consequences of the left-behind children phenomenon, urging expedited hukou reforms.
Hi, this is Yuxuan Jia from Beijing. Following Lu Ming's presentation, today's post focuses on a quantitative econometric study examining the causal relationship between being left behind in childhood and committing crimes in adulthood. Same as Professor Lu, this presentation was originally delivered at an April 27 online seminar organized by Hongfan Legal and Economics Studies, with the seminar video still available online.
The presenter, Zhang Dandan, is a Professor in Economics (with tenure) and Deputy Dean (in research, internal and international cooperation) at the National School of Development, Peking University. She was also featured on The East is Read in July 2023 for her study on the youth unemployment rate in China.
Hongfan provided The East is Read with a text transcript of the seminar. The seminar was hosted by Wang Yong, Director of Hongfan Legal and Economics Studies and Professor of Law at the China University of Political Science and Law.
Zhang's study uncovers a strong correlation between being left behind and criminal behavior. Key figures are:
If one parent is absent due to work, the likelihood of the child engaging in criminal activity as an adult increases by 2.5% to 3.2%.
For each additional year a child spends without their parents, the probability of committing a crime increases by 0.4%.
Left-behind children receive, on average, 0.8 fewer years of education compared to their peers who live with their parents.
Left-behind children have a 12.1% higher probability of gambling and are more likely to take loans.
Continuing from Professor Lu Ming's discussion, I would like to delve deeper into some of the issues raised. Professor Lu primarily addressed urbanization, the migration of populations to large cities, and the inclusion of migrant families, particularly their children. My research focuses more narrowly on the long-term impact of being left behind on children in rural areas and how this experience influences their propensity for criminal behavior in adulthood. Today, I want to share some robust evidence with you, so I've brought this research for discussion.
Data collection for this research began in 2015 but was released only last year due to a typically lengthy publication process in economics. It appeared in a top-tier journal in behavioral economics. Here is a summary of the key findings.
Our research targeted the rural-urban migrants in 2015, specifically examining the question: Does being "left behind" in childhood lead to criminality in adulthood? The cohort we studied was primarily born around 1990 and were in their mid-20s by 2015. The proportion of left-behind children was significantly lower during this period compared to today. According to Professor Lu, the number of left-behind children began to increase markedly after 2010.
Our study focused on those left behind between 1990 and 2000, during their formative years of 0-15. The long-term impacts we observed from this period, despite the lower proportion of left-behind children, underscore the urgent need to address this issue now, given the rise in their numbers.
Director Wang Yong also raised a pertinent question: Is it too late to address this issue now? I believe it's not; we must act promptly. Currently, a quarter of Chinese children are left behind, and another quarter are migrant children, collectively accounting for half of all children aged 0-28 in China. As these children enter the workforce in about a decade, their early experiences will significantly influence their adult behavior. My research aims to provide evidence from earlier migrant populations to explore the potential social consequences of the left-behind phenomenon.
This paper, which I co-authored with Lisa Cameron from the University of Melbourne and Professor Xin Meng from the Australian National University, investigates the long-term impacts of being left behind during childhood.
To provide some context, the academic community has long been interested in the consequences of children being left behind, with numerous studies dating t the 2010s. Most existing research focuses on the immediate effects on the health and education of left-behind children. These studies have found that left-behind children often experience lower educational attainment, higher dropout rates, poorer health due to lack of parental supervision, and less time for educational or developmental activities as they may be more engaged in farm work or household chores. This consensus highlights the immediate negative impacts.
However, there is a gap in research regarding the long-term effects, particularly in terms of criminal behavior in adulthood. Our study aims to address this gap.
In 2015, we conducted our research in a man's prison in China. We focused on males because over 90% of incarcerated individuals are men, who have higher crime rates. We randomly selected 2,000 inmates, roughly a quarter of the prison population, and conducted behavioral experiments with 1,200 of them due to funding constraints. Our sample was thus based on these 1,200 individuals.
Notably, 85% of the 1,200 inmates had a background as migrant workers before their incarceration, indicating a high proportion of migrants within the prison population compared to approximately 50% among the general population in the regions we studied. This suggests that migrant populations have a higher likelihood of criminal behavior.
However, this higher likelihood is probably influenced by demographic factors such as age and the predominantly male migrant worker population. To address this, we built a sample of incarcerated individuals from a migrant background and compared them with 300 randomly selected representative samples from the region we researched. These 300 samples represent the general male migrant worker population in the area. We conducted identical surveys for both groups—incarcerated individuals and ordinary migrant workers.
Our survey included various terms, which I will briefly outline. First, we tried to define being "left behind." Many studies on this topic have different definitions. For instance, as mentioned by Professor Lu Ming, the 2020 definition of "left behind" refers to children aged 0-18 whose parents are absent at the census point (November 1st). If a child is with their parents at that point, they are considered part of the "migrant population." This definition is specific to a single point in time.
In many other studies, researchers consider whether children's parents have ever worked away from home or if they have ever been left behind. This perspective shows a higher proportion of affected children, as it accounts for the dynamic nature of their parents' migration status.
Our study focuses on a more sustained experience of being left behind during childhood. We define "left behind" as children aged 0-16 who spent most of their formative years without living with their parents. Specifically, we ask if the child's parents were away due to work for most of the child's upbringing. We exclude cases where parental absence was due to divorce or death, focusing only on those caused by parents working away from home.
Because our definition of "left behind" involves a prolonged period, the proportion in our study is lower than in other data sets, with only 7% of the children fitting this criterion. We also examined the duration of parental absence, finding that the most common range was three to six years. This prolonged absence aligns with our "deep left-behind" definition, differentiating our study from others by focusing on long-term parental absence due to work rather than short-term or other reasons.
Comparing the two samples, we found that the proportion of "deeply" left-behind individuals is significantly higher among incarcerated individuals than among ordinary migrant workers. In the incarcerated sample, 14% experienced deep left-behind status, compared to 6.9% in the ordinary migrant worker sample, with an overall average of 7%.
Thus, our findings indicate that those who experienced being "deeply" left behind during childhood are more likely to end up incarcerated than those who did not.
To understand how being left behind leads to criminal activities among adult males, we examined how this experience influences various factors during their upbringing. As Director Wang Yong and Professor Lu Ming mentioned, aspects such as education, psychology, and behavior might be altered or distorted due to being left behind, resulting in a higher likelihood of criminal behavior in adulthood. These factors are central to our research framework, which necessitated designing specific experiments.
Our experiments involved both incarcerated individuals and a control group of ordinary migrant workers, using games and payment incentives to reflect their true behavioral habits. These games assessed traits like altruism, risk preferences, trust in others, and honesty. The design and implementation of these games were identical for both samples, allowing for direct comparisons. After the games, we collected detailed survey data through one-on-one interviews with each participant.
The total sample size for this study was over 900, following rigorous selection processes. Each participant underwent tests for the Big Five personality traits, psychological assessments, IQ tests, and time preference tests, alongside basic questionnaires about their family background and childhood experiences, including specific questions about being left behind. We also accessed administrative data from the prison system to validate the information provided by the incarcerated participants.
The design of our games was based on classic behavioral economics literature, with some modifications to suit our research context. For instance, the time preference games were used to determine if an individual was patient or impulsive, as impulsivity is often linked to criminal behavior.
Having outlined the structure and components of our survey and experiments, I will now present the main conclusions from our research:
There is a very strong correlation between being left behind and criminal behavior. Our data indicates that if one parent is absent due to work, the likelihood of the child engaging in criminal activity as an adult increases by 2.5% to 3.2%. This effect is significant and undeniable.
Regarding the duration of being left behind, for each additional year a child spends without their parents, the probability of committing a crime increases by 0.4%.
To ensure that this relationship is causal and not merely correlational, we employed various methods to isolate the effect of being left behind from other potential factors. While I won't go into the technical details here, the results consistently confirmed our initial findings.
Using instrumental variable techniques, the estimated impact is even higher, suggesting a 7.5% increase in the likelihood of criminal behavior, with each additional year of being left behind raising this probability by 7%.
Next, we explored the channels through which being left behind affects behavior, addressing Director Wang Yong's question about the factors leading to behavioral distortions in these children. We focused on risk preference and patience (time preference), as these traits are highly correlated with criminal behavior according to existing literature.
Our findings indicate that left-behind children have a significantly higher propensity for risk-loving. The proportion of individuals with high-risk preferences is notably greater among this group. Additionally, these children exhibit lower patience levels, although this result was not statistically significant.
We also examined the Big Five personality traits, which are standard in psychology. We found evidence suggesting that children whose parents work away from home tend to have more emotional instability, indicating that parental absence affects their personality.
Another major factor is education. Left-behind children receive, on average, 0.8 fewer years of education compared to their peers who live with their parents. Using instrumental variable techniques, the reduction in education is estimated to be about 1.5 years. This range (0.8 to 1.5 years) indicates a substantial educational deficit for left-behind children compared to those not left behind.
These factors—risk preference, time preference, personality, and education—are all potential contributors to the higher likelihood of criminal behavior. We conducted an attribution analysis and concluded that the primary factors are education and risk preference. The other two factors (time preference and personality traits) also play a role, but their impact is relatively smaller.
In addition to criminal behavior, we investigated gambling behavior. During our prison interviews, we found that many inmates with a background of being left behind engaged in gambling activities, such as betting on lotteries during middle school. Our analysis confirmed that left-behind children have a 12.1% higher probability of gambling and are more likely to take loans, leading to higher debt levels in adulthood.
In conclusion, our extensive efforts in building this dataset and developing our econometric model, conducted in an empirical approach, aim to convey a crucial message: the phenomenon of family separation and the issue of left-behind children in China have long-term social consequences. Although there might not be immediate negative effects from the hukou system or other policies, these issues can manifest through increased criminal behavior, affecting society over the long term. Short-term impacts are also evident, as seen in rising juvenile delinquency and other social incidents.
Our research identifies the channels of influence that affect these children's behavior. It is essential to regulate their behavior, help them develop healthy personalities and values, and improve their education to mitigate the potential long-term negative social consequences of being left behind. We hope to see substantial action soon, such as the educational reforms mentioned by Professor Lu Ming, which aim to provide these children with equal educational opportunities and more time with their parents to experience familial bonds and reduce the likelihood of criminality in adulthood.
As Professor Lu highlighted, a quarter of children in 2020 were left behind. These children will enter the labor market and reach adulthood in the next decade, and their propensity for criminal behavior needs to be addressed now. The current proportion of left-behind children might be even higher than in 2020, underscoring the need for attention from policymakers and society as a whole.
Thank you.
