3
allows us to examine the extent to which the paradox of healthier behavior among foreign-born
mothers is unique to the Hispanic population in the U.S., or if it spans groups from disparate
regions. In addition, the similar socioeconomic profiles within markedly different health care
systems allows us to examine the extent to which differences in healthcare infrastructure mitigate or
exacerbate immigrant-native differences in maternal health behavior. Given that prenatal care is free
in the UK, and given that all new mothers participate in home visiting programs, we might expect to
find better health behaviors among all U.K. mothers relative to U.S. mothers. We might also expect
to find less of a gap between native-born and immigrant mothers in the U.K., assuming that both
groups are receiving good prenatal care and information. Because we are comparing only two
countries and are not testing the influence of one specific policy, we cannot draw any firm
conclusions about the consequences of the two health care systems. However, we view this
comparison as a first step at understanding the ways in which health policies are associated with
maternal health behaviors and how this differs for native-born and immigrant mothers.
We uncover four important findings. First, the “Hispanic paradox” extends not only to
other socioeconomically disadvantaged immigrant groups, but also to more advantaged mothers.
Secondly, in both settings these differences are fairly stable over children’s early life course; we find
no consistent evidence for processes of convergence or divergence between groups. Third, in
neither the U.S. or the U.K. do differences in mothers’ social and instrumental support play a strong
explanatory role in accounting for the immigrant advantage. Finally, we find that the foreign-born
advantage in health behavior is equally strong in the U.K. These findings lead us to propose that
families who migrate do so with the welfare of their current or future children in mind. The
migration literature has long focused on migration as an investment in socioeconomic mobility (e.g.,
Todaro 1976). Similarly, scholars of migration and health have often pointed to the potential health
4
selectivity of migrants (e.g., Landale, Oroporsa and Gorman 2000; Jasso et al. 2004). We propose a
broader view of immigrant selectivity, one in which migrants are selected not only on health, but
also on their desire to maximize the welfare of their children. In addition to being a socioeconomic
investment, migration may also be a parental investment.
THE HEALTH INCORPORATION OF FOREIGN-BORN MOTHERS
Nativity Differences at Birth
Mothers’ health behaviors are of special interest because they reflect children’s home
environments and are strongly related to children’s own health. Existing research on nativity
differences in health behavior in the U.S. has produced important findings, particularly for the
period around birth. Foreign-born, Hispanic mothers, for example, are more likely than native-born
mothers to fully immunize their children and to breastfeed, especially if they are “less acculturated”
(Anderson et al. 1997; Kimbro et al. 2008). Rates of infant mortality and low birth weight are also
significantly lower among foreign-born, Hispanic mothers. These patterns vary within the Hispanic
population: the prevalence of low-birth-weight is above-average among Puerto Rican-born mothers,
for example, and below-average among Mexican, Cuban and Central/South American mothers
(Landale, Oropesa and Gorman 1999). Evidence among non-Hispanic mothers and infants is less
clear; while there is some evidence that foreign-born mothers from East Asian and South Asian
countries are less likely to give birth to low-birth-weight babies, Filipino mothers have above-
average levels of low birth weight (Landale, Oropesa and Gorman 1999). Existing research tells us
little about whether the foreign-born health advantage extends across the socioeconomic spectrum.
Do Nativity Differences Persist into Early Childhood?
Despite the common focus on the period of infancy, our knowledge of the evolution of
nativity differences over time is quite limited. To address the question of whether foreign-born
mothers’ health behavior deteriorates with increased time in the destination country, researchers
5
ideally should examine behavioral trajectories within the same mothers over time. Because such data
have not been readily available, researchers typically rely on cross-sectional comparisons of mothers,
stratified by generational groups. Using this approach, they find that foreign-born women’s health is
better than that of their peers from later generations (Antecol and Bedard 2006; Gordon-Larsen,
Adair and Popkin 2003). Similarly, researchers who stratify by number of years in the U.S. find that
immigrant-native differences become smaller with increasing lengths of time in the United States
(e.g., Antecol and Bedard 2006). Unfortunately, comparing across generational groups or measuring
the number of years in the U.S. does not fully reveal whether different groups have different
trajectories. Within the foreign-born, for example, there may be important compositional
differences that vary with the year of arrival, including the context of reception, reason for
migration, or socioeconomic circumstances. These differences may produce variation across
generational groups that has little to do with individual trajectories.
Existing studies suggest that the health advantage of foreign-born mothers should decline
over time (e.g, Antecol and Bedard 2006). In this scenario, a process of convergence occurs, whereby
the deterioration of mothers’ health behavior is more rapid within the foreign-born population than
within the native population. This process has been observed in the U.S. with respect to trajectories
of weight gain among adolescents (Jackson 2009). Residential, family and socioeconomic factors
provide one potential explanation for convergence across nativity groups: adults, for example, may
alter their levels of physical activity and eating habits (Akresh 2007; Morales et al. 2002) to become
more in line with native-born peers in their environments, and in the composition of their kin and
non-kin networks. Alternatively, a process of divergence may occur, whereby foreign-born parents and
children maintain healthier behaviors over time. First-generation families may benefit from a
combination of dense ethnic networks and increases in family socioeconomic status, providing a
6
layer of support that makes it easier for them to maintain healthy behaviors as children age. Finally,
it is possible that nativity differences remain stable over time. Stability does not necessarily predict
equality across nativity groups, but rather no significant temporal change in the gaps.
It is impossible to study trajectories without also being aware of health selectivity. Migration
processes can drive observed patterns of convergence or divergence upward or downward for
several reasons. If those who migrate are in fact the healthiest of their sending populations, then
some degree of "regression to the mean" is inevitable (Jasso et al. 2004). Factors related to the
migration process—that is, who migrants are and whether they fully represent their sending
populations—should therefore be considered along with contextual factors as possible explanations
for nativity differences, as well as changes in their size over time.
DIFFERENCES IN ACCESS TO SOCIAL SUPPORT: A POSSIBLE EXPLANTION?
Existing research on the health integration of foreign-born mothers and children offers little
explanation for immigrant-native differences. Strong nativity differences at birth may reflect either
differences related to migration and the composition of immigrants vs. natives, or differences in the
host environment, summarized by Jasso et al. (2004: 240) as the migration models of "initial
selectivity" vs. "subsequent trajectory." With respect to selectivity, foreign-born mothers may
represent the healthiest members of their native population, therefore not fully representing the
sending population and driving estimates of the foreign-born advantage in health and health
behaviors upward. There is surprisingly little empirical evidence for this idea, largely because of the
lack of data permitting comparison of immigrants to the population in both their sending and
receiving countries. Existing research suggests little evidence of health selectivity among Mexican
adults (Rubalcava et al. 2008), but stronger health selection among Puerto Rican mothers, (Landale,
Oropesa and Gorman 2000).
7
We consider differences in migrants' support systems, which are a product of both the
resources that migrants bring with them as well as their circumstances upon arrival. Specifically, we
examine three aspects of support systems: household composition (including the presence of a
spouse), instrumental support, and social integration. The presence of additional adults within the
household to assist with caring for the child and making decisions is expected to provide a support
buffer against stressful circumstances that might otherwise lead to mothers' adoption of unhealthy
behaviors (e.g., Kiernan and Mensah 2009; Meadows et al. 2008). Extra-household support
networks may also play a role in structuring mothers' health behaviors related to their own and their
children's health. In particular, mothers may benefit from the presence of both resource-related
support, or instrumental support, and interaction-based support, indicative of the degree of their
social integration. Families who can rely on someone for short-term financial or child care
assistance are more likely to be able to maintain low levels of stress and healthy behaviors. In
addition, socially integrated mothers have more readily available access to networks of other parents,
providing information and social norms that can aid in health-related decision-making (Berkman and
Glass 2000). Both forms of support also reflect a certain degree of strength in social ties and buffers
against social stressors, the presence of which is strongly associated with health behaviors, morbidity
and mortality (House 2001; Thoits 1995).
Evidence on nativity differences in support systems is clearer with respect to within-
household networks than for social ties outside of the household. There are striking differences in
family and household composition between migrant vs. native families. Children growing up in
immigrant families are more likely than natives to live with both parents (Landale, Oropesa and
Bradatan 2006). This is also the case in the U.K. except for families from the Caribbean and Africa
(Platt 2009)). In addition, extended family residence arrangements are more common in foreign-
8
born households (Roschelle 1997): 12% of all U.S. households in 1990 contained extended family
members, compared to almost 30% of foreign-born households (Glick, Bean and Van Hook 1997).
Similarly, in the U.K., 10% of South Asian families in 2001 contained three generations as compared
with 2% of all U.K households (Dobbs et al 2006). Theory and evidence on nativity differences in
extra-household social ties is more mixed. Whereas some argue that migration reinforces social ties
(Rumbaut 1997), others point out that geographic mobility disrupts social ties in the sending
community, thereby reducing the size of migrants' social networks (Hagan, MacMillan and Wheaton
1996; Portes 1998). Consistent with this argument, Landale and Oropesa (2001) find that Puerto
Rican mothers of young children in the U.S. have lower levels of social support than both natives
and Puerto Rican women living in Puerto Rico. Accordingly, they also find that nativity differences
in social support do not explain birth outcome differences.
Migrants' support systems are comprised of both the resources that they bring with them
(within-household composition) as well as those that they accrue in the host country (extra-
household networks). Examining these differences, as well as how they relate to health, provides
empirical leverage on the question of what lies behind nativity differences in health behaviors.
A COMPARATIVE LENS
The United Kingdom provides a useful case for both extending our understanding of the
Hispanic paradox to a broader range of foreign-born groups, as well as providing a point of
comparison to U.S. patterns. Despite a longstanding interest in migrant health in the U.K. (Marmot
1993), research on nativity differences in mothers' and children's health behaviors and outcomes has
been limited. Although registration data have provided information on infant mortality and low
birth weight (e.g., Collingswood Bakeo 2006), survey data that allow researchers to examine these
issues have only recently become available (Hawkins et al. 2009; Panico et al. 2007). 2007 British
9
statistics show that 11% of the British population is foreign-born, and 20% of children and
adolescents below the age of 18 are either foreign-born or the child of one or more foreign-born
parents. Today there are sizeable populations of non-white immigrants from South Asia (India,
Pakistan and Bangladesh), Africa and the Caribbean. At the time of the 2001 Census, Indians were
the largest minority group, followed by Pakistanis, Black Caribbeans, Black Africans and those of
mixed ethnic background; smaller groups include Bangladeshi and Chinese minorities (White 2002).
Among British migrants, socioeconomic profiles differ substantially. Whereas migrants from
the Caribbean, Pakistan and Bangladesh have lower education and occupational qualifications than
whites, on average, those from India, Africa and China have higher average qualifications (Modood
2003). Although black Caribbean migrants have very low levels of high professional qualifications,
Pakistanis and Bangladeshis are more internally polarized, with both poorly and very highly qualified
migrants. U.S. research examining nativity differences in socioeconomic status also demonstrates
differences across ethnic groups. Foreign-born Mexican men and women, who comprise the largest
U.S. immigrant group, earn less than U.S born Mexican-Americans and non-Hispanic whites
(Allensworth 1997; Verdugo and Verdugo 1985). Beyond the Mexican case, those born in Central
or South America also gain less financially from education than their native-born peers (Tienda
1983); these patterns changed little during the period between 1970 and 1990 (Snipp and
Hirschmann 2005). Asian-born adults are internally polarized, clustered at both the top and bottom
of the socioeconomic hierarchy (Zeng and Xie 2004). As a whole, however, there is evidence that
Asians broadly categorized are more successful than the equally broad Hispanic group in converting
education into economic and occupational success (Iceland 1999; Niedert and Farley 1985).
The very different composition of the foreign-born population in the U.K. relative to the
U.S., as well as the diversity of socioeconomic profiles and ethnicities in each setting, allows for a
10
broader consideration of the "immigrant paradox." On the one hand, generally similar social and
demographic conditions in the U.S. and U.K. might lead to a similar incorporation process among
migrants into each context. Both countries share similar patterns of family formation (Platt 2009)
and socioeconomic inequality: income inequality is higher in the U.S. (e.g., Banks et al. 2003) but
levels in both societies are high and have increased over the last several decades (Wilkinson and
Pickett 2009). On the other hand, there are important structural differences between the U.S. and
U.K. that may produce smaller disparities between the foreign-born and natives in the health
behaviors of mothers and children. Free health care provided through the British National Health
Service, as well as more generous policies related to home visits, priority medical appointments for
children, and child centers which provide integrated child care services, may make it easier for all
families to maintain adequate health care, healthier behaviors and outcomes. More generous policies
also exist in the U.K. with respect to family assistance and social housing (Gornick and Myers 2005;
Hills 2007). Although we cannot directly test the influence of these policies, the different social
programs aimed at reducing disparities among families and children suggest that we may observe
weaker inequalities in the U.K.
DATA AND METHODS
Data
Our analysis is based on two national birth cohort studies well suited to studying nativity
differences in health behaviors: the American Fragile Families and Child Wellbeing Study (FFS) and the
U.K. Millennium Cohort Study (MCS). Both studies are representative of national populations, contain
rich longitudinal information on families’ and children’s contexts and health, and oversample ethnic
minority families.
11
FFS. The FFS is a national birth cohort study following approximately 5,000 children born
in large U.S. cities between 1998 and 2000, including a large oversample of births to unmarried
parents. When weighted, these data are representative of births in cities with populations over
200,000. Mothers, and most fathers, were interviewed in the hospital soon after birth. The initial
interviews were followed by telephone interviews with both parents when the child is 1, 3, and 5
years old; the 9 year interview is currently in the field. These “core” interviews provide information
on socio-demographic characteristics, parents’ health, parental relationships, parenting, and child
wellbeing. At ages 3 and 5, the child’s primary caregiver (typically the child’s mother) participated in
an additional in-depth interview and assessments focusing on parenting, child health and
development.
MCS. The MCS is the fourth of Britain’s national longitudinal birth cohort studies,
providing information about children and their families in the four countries of the United
Kingdom. The first wave, carried out during 2001-2002, included 18,552 families and 18,818 cohort
children. Information was first collected from parents when the babies were nine months old. The
sample design allowed for an over-representation of families living in areas with high rates of child
poverty or high proportions of ethnic minority populations. The first wave provided information
on the circumstances of pregnancy, birth and the early months of life. The main caregiver (in most
instances the mother) was interviewed again when the cohort child was age 3 years, 5 years and 7
years (age 7 data are not yet available). These interviews and the baseline survey provide detailed
information on the demographic, social and economic situations of the families and the health and
well-being of the children and their parents.
Measures
12
Mothers’ Health Behaviors. We examine mothers’ health behaviors at the time of the
child’s birth, and between birth and age 5. Our focus is on behaviors that are meaningfully and
directly related to both mothers' and children's health, and comparable across the two data sources;
this allows us to provide a comprehensive picture of maternal inputs into child health. At the time
of the child’s birth in both surveys, we measure breastfeeding initiation (yes/no) and smoking during
pregnancy (yes/no).
1
Prenatal drinking is a trichotomous indicator in the FFS (never, sometimes,
often), and a 5-point scale in the MCS, ranging from never to more than 3 times/week. In each
survey we measure early prenatal care by distinguishing among mothers who first sought care in the
third, second or first trimester for pregnancy. Later in childhood, from ages 1-5, we measure
mothers’ smoking behavior around the child (smokes/does not smoke around child) as well as mothers’
frequency of drinking. In the FFS, we create a measure of binge drinking indicating whether mothers
drink at least 4 alcoholic beverages per day. In the MCS, we create a 5-point scale ranging from
never to more than three times/week.
2
Nativity and Race/Ethnicity. Although all children are born in either the U.S. or U.K.,
mothers may be foreign-born. We separate foreign-born mothers (first-generation) from those born
in the U.S. or U.K. (second generation). Within the foreign-born group we separate mothers by
ethnicity. In the FFS we distinguish between Hispanic and non-Hispanic foreign-born mothers.
Small sample sizes prevent us from disaggregating further by ethnicity either within or outside of the
foreign-born group; close to 60% of foreign-born Hispanic mothers identify themselves as Mexican,
with other mothers distributed across Puerto Rican, Cuban and other Hispanic ethnicities. In the
1
We recognize that distinguishing among levels of prenatal smoking and drinking is potentially important (e.g., Kelley,
Day and Streissguth 2000). In the MCS, there are not enough cases in each nativity group when we create a smoking
trichotomy distinguishing among no, low/medium and heavy prenatal smoking, so we proceed with the dichotomous
measure. Similarly, a measure indicating more frequent drinking (number of drinks per day) in the MCS, where such
information is available, does not provide enough variation by nativity.
2
Again, although we recognize that this measure is not ideal, very small to nonexistent sample sizes prevent us from
using a more stringent drinking measure in the MCS.
Không có nhận xét nào:
Đăng nhận xét