Skip to ContentSkip to Navigation

Aletta Jacobs School of Public Health

Together for more healthy years
Aletta Jacobs School of Public Health
Header image AJSPH

AJSPH

Keynote Gerard van den Berg - Using the migrating siblings design to identify sensitive childhood ages for adult health and education

Datum:15 oktober 2019
Gerard van den Berg
Gerard van den Berg

Gerard van den Berg, chair of the Aletta Scientific Council, will be the first keynote speaker during the Aletta Research Meet-up on 5 November. Van den Berg is a professor of Economics at the University of Bristol. However, the economist will soon return to the Faculty of Economics and Business at the University of Groningen; the faculty where van den Berg obtained his BA titles and MA in the early 80’s.

Gerard van den Berg is a world leader in the field of econometrics. As well as econometrics he also conducts research in the fields of labour economics and health economics, notably on duration analysis, treatment evaluation, search theory, and long-run effects of early-life conditions.

The importance of health origins early in life
In his keynote, van den Berg will talk about exposure in association with good and bad economic conditions, effects on the level of education, on physical and mental health, and on economic performance later in life. Van den Berg states it is important to understand the determinants of health later in life because this helps to design health care policy and predict the usage of health care in the future: “Now, health at high ages may have many origins, but it is particularly important to know health origins early in life. Why? First of all, a bad start in life may affect many things throughout the full lifespan, so the period in which the costs are incurred is much, much longer than if something bad happens at a high age. Consider being born in a famine. This may lead to lower cognitive performance for many years before retirement, so the economic loss is very high compared to those not born in a famine.”

A second reason to be focused on childhood circumstances is that there is a long time span after childhood and before high age, and during that time span, interventions can be used to mitigate a bad start in life. Van den Berg: “We may target preventive interventions towards those who experienced a childhood in adverse conditions, such as children in refugee families.”

Is diabetes the result of the poverty?
Because it is difficult to understand the cause of poverty in adolescence it is not an easy research to do. Van den Berg: “We cannot do experiments in which we manipulate in what kind of environment children grow up. In real-life data we may, for example, observe that a child who experienced poverty in adolescence has a higher risk of diabetes later in life. Is the diabetes the result of the poverty? Maybe not. Maybe the poverty in adolescence is the result of something that happened around birth of the child; something that is responsible for diabetes in late life. Then the real problem is not the poverty in adolescence but the adversity around birth. Or maybe the poverty reflects the health and wealth of the parents and other ancestors. Then it would be better to focus on that instead of on conditions during adolescence. You don’t want to spill resources by helping those who were poor in adolescence but come from a wealthy background and faced good conditions in early childhood, because they are highly unlikely to get diabetes anyway.”

Exposing young individuals to shocks
To better understand the relation between the circumstances in childhood and the impact it has on a person’s health later in life van den Berg uses two methods: “First, we use shocks in the life of young individuals that affect the whole society. Examples are recessions, famines and epidemics. These shocks are unexpected and last at most a few years. We can then see if the people that were exposed to such a shock at a certain childhood age develop health problems later in life.”

Van den Berg developed the second method in collaboration with Petter Lundborg, who, coincidentally, is also a member of the Scientific Council of the Aletta Jacobs Public School of Health. Van den Berg: “We look at siblings who were part of families that immigrated during their childhood. As an example, consider two brothers who were 11 and 13 years old when the family immigrated from a poor to a rich country. The brothers migrated at the same time but at different ages. If we find that the late-life health of the older sibling is much worse than the late-life health of the younger sibling, then this indicates that the economic conditions at age 12 are very important for health later in life. After all, the younger sibling experienced his 12th year in the rich country while the older one was still in the poor country at age 12. And otherwise their conditions in childhood were very similar. Of course, to draw conclusions one needs very large datasets of immigrating siblings. But we have shown that this is feasible, and in the presentation I will give some examples, from Sweden and from Italy.”

Research on family trees in a Swedish remote village
During his keynote van den Berg will also briefly focus on the effects on the next generations of those exposed. “In the past decades, researchers have made some amazing discoveries using family trees in a very remote village in North Sweden. The remoteness of the village meant that food surpluses and shortages due to unusual harvests immediately led to great abundance or lack of food, at least in the 19th century. It turns out that the grandchildren of people who experienced unusual harvest conditions just before puberty have unusual health outcomes themselves later in life. For a long time, this was seen as a freak result, and the researchers had a hard time getting it published. However, many of their findings are supported by animal experiments, and the academic community has become more welcoming for such work. I have been involved in similar studies for Germany and for other parts of Sweden, and we find similar effects.”

T’ai-chi for elderly
So what kind of policy could help people born in poverty not to become unhealthy? Van den Berg: “There is more and more evidence that the pathway is biological and difficult to influence. In this sense the relevance may be more in terms of identifying who are the people at risk, and then monitoring them to prevent that things get out of hand, for example with cardiovascular problems or diabetes.” According to van den Berg there is also some speculative evidence that for elderly it helps to do t’ai-chi and meditation in order to dampen these kinds of long-run effects: “But whether this can establish a permanent improvement is very much an open question.”

Contest between social science and biology
What does van den Berg want to achieve with his research? “Ultimately I see this kind of research as a contest between social science and biology. To what extent can the causes be avoided by socio-economic policy? To what extent are the mechanisms biological and irreversible? And to what extent can social science bring evidence of beneficial behavioral adjustments? I would like to contribute to our understanding of these issues. I hope that this ultimately helps to improve the life quality of those who experience adverse conditions early in their life.”

Check our event page for more information about the Research Meet-up.