Stockholms universitet

Martin KolkForskare, Docent

Om mig

I am a researcher and Docent (Associate Professor) at SUDA (Stockholm University Demography Unit), ÅA in Vaasa (Åbo Akademi), and IFFS (Institute for Future Studies), working on various aspects of intergenerational demography, kinship, economic demography, LBGT demography, and social stratification. Many of my research interests are about the demography of kinship and economic demography in contemporary and historical populations. Currently, I use linked register and parish data with micro-level data to examine demographic change from the mid-18th century until today. I am also working with researchers in the program for historical demography at Academica Sinicia in Taipei, Taiwan.

My research interests are often related to intergenerational demographic processes, and I have written papers on many areas of demography, including fertility, mortality, migration, same-sex union formation and childbearing, and early life effects on demographic outcomes. I am interested in cultural evolution, and in particular, the relationship between cultural evolution and demographic processes. I have also written papers on population ethics and social stratification.

I have also written several Swedish language reports for different government agencies, including a Covid-19 report on mortality for the Public Health Agency, a report on the demography of China, and a report on future censuses in Sweden.

Recent studies include; kinship and stratification, long-term consequences of intergenerational transmission of fertility, age differences in unions, cohort approaches to migration, and influences of family composition in childhood on various demographic outcomes. 

My Google Scholar page is available here and my CV can be found to the right.

Most of my publications are available for everyone to download using this link.


Recent Publications (since 2019):  

Xia, Weiqian, Martin Kolk and Jan Saarela (2024) “Socioeconomic advantage or community attachment? A register-based study on the secularization difference between Finnish and Swedish speakers in Finland “Journal for the Scientific Study of Religion, accepted for publication

Saarela, Jan, Martin Kolk, and Ognjen Obućina. (2024) “Kinship, Heritage and Ethnic Choice: Ethnolinguistic Registration across Four Generations in Contemporary Finland” European Sociological Review, accepted for publication

Barclay, Kieron, Martin Kolk and Øystein Kravdal (2024) ”Birth spacing and the health of mothers and fathers: an analysis of physical and mental health using individual-and sibling-fixed effects” Demography, accepted for publication

Kolk, Martin and Jan Saarela (2024) “Religion and Fertility – A Longitudinal Register Study Examining Differences by Sex, Parity, Partner’s Religion, and Religious Conversion in Finland“ European Journal of Population. accepted for publication

Engström Emma and Martin Kolk (2024) “Projecting Environmental Impacts with varying Population, Affluence, and Technology using IPAT–Climate Change and Land Use Scenarios “Vienna Yearbook of Population Research, accepted for publication

Andersson, Linus and Martin Kolk (2023) ”Kinship and Socioeconomic Status: Social Gradients in Frequencies of Kin Across the Life Course in Sweden” Population Studies, available online

Shi, Jiaxin and Martin Kolk (2023) ”The inequality of lifetime pensions” Sociological Science, 10(24): 667-693

Campbell, Tim, Martin Kolk, and Julia Mosquera (2023) ”Universal procreation rights and future generations” Journal of Applied Philosophy, available online

Kolk, Martin, Linus Andersson, Emma Pettersson, and Sven Drefahl. (2023) ”The Swedish Kinship Universe – A demographic account of the number of children, parents, siblings, grandchildren, grandparents, aunts/uncles, nieces/nephews, and cousins using national population registers” Demography,  60(5): 1359–1385

Hällsten, Martin, and Martin Kolk (2023) “The shadow of peasant past: Seven generations of inequality persistence in Northern Sweden” American Journal of Sociology, 128(6): 1716-1760 

Saarela, Jan, Martin Kolk, Caroline Uggla (2023) “Divorce among exogamous couples: the role of language convergence” Acta Sociologica, 66(4): 402-420

Kolk, Martin (2023) “The relationship between lifecourse accumulated income and childbearing of Swedish men and women” Population Studies, 77(2): 197-215

Shi, Jiaxin and Martin Kolk (2022) “How Does Mortality Contribute to Lifetime Pension Inequality? Evidence From Five Decades of Swedish Taxation Data” Demography, 59(5): 1843–1871

Kolk, Martin and Vegard Skirbekk (2022) “Fading Family Lines - Women and men without children, grandchildren and great-grandchildren in 19th, 20th, and 21st century Northern Sweden” Advances in Life Course Research, 53: 100481

Gardner, Eugene J., Matthew D. C. Neville, Kaitlin E. Samocha, Kieron Barclay, Martin Kolk, Mari E. K. Niemi, George Kirov, Hilary C. Martin, and Matthew E. Hurles (2022) “Reduced reproductive success is associated with selective constraint on human genes” Nature, 603: 858–863

Grätz, Michael and Martin Kolk (2022) “Sibling Similarity in Income: A Life Course Perspective” Research in Social Stratification and Mobility, 78: 100688

Kolk, Martin and Karim Jebari (2022) “Sex Selection for Daughters: Demographic Consequences of Female-biased Sex Ratios” Population Research and Policy Review, 41: 1619–1639

Kolk, Martin, Sven Drefahl, Matthew Wallace, Gunnar Andersson (2022) "Excess mortality and COVID-19 in Sweden in 2020: A demographic account” Vienna Yearbook of Population Research, 20: 317-348

Alburez-Gutierrez, Diego, Martin Kolk, and Emilio Zhageni (2021) “Women's experience of child death over the life course: A global demographic perspective” Demography, 58(5): 1715-1735

Cheng, Yen-hsin Alice and Martin Kolk (2021) “An East–West dichotomy? Shifting marriage age patterns in Taiwan and Sweden over two centuries” History of the Family, 26(3): 434-465

Kolk, Martin (2021) “Government transfers to parents and population policy in a global perspective: An economic demographic approach” Journal of Development Studies, 57(9): 1483-1498               

Saarela, Jan and Martin Kolk (2021) “Birth order and alcohol-related mortality by ethnic origin and national context: Within-family comparisons for Finland and Sweden” Drug and Alcohol Dependency, 226: 108859

Kolk, Martin and Kieron Barclay (2021) “Do income and marriage mediate the relationship between cognitive ability and fertility? Data from Swedish taxation and conscriptions registers for men born 1951-1967” Intelligence, 84: 101514

Comolli, Chiara, Gerda Neyer, Gunnar Andersson, Lars Dommermuth, Peter Fallesen, Marika Jalovaara, Ari Jónsson, Martin Kolk, and Trude Lappegård. (2021) ”Beyond the Economic Gaze: Childbearing during and after recessions in the Nordic countries” European Journal of Population, 37: 473–520

Barclay, Kieron and Martin Kolk (2020) “The Influence of Health in Early Adulthood on Male Fertility” Population and Development review, 46(4): 757-785                                                        

Saarela, Jan and Martin Kolk (2020) “Alcohol-related mortality by ethnic origin of natives: A prospective cohort study based on multigenerational population register data from Finland and Sweden”, BMJ Open, 10: e042234

Brandén, Maria, Siddartha Aradhya, Martin Kolk, Juho Härkönen, Sven Drefahl, Bo Malmberg, Mikael Rostila, Agneta Cederström, Gunnar Andersson, and Eleonora Mussino (2020): Residential Context and COVID-19 Mortality among Older Adults in Stockholm: A population-based, observational study. Lancet Healthy Longevity, 1(2): e80-e88

Drefahl, Sven, Matthew Wallace, Eleonora Mussino, Siddartha Aradhya, Martin Kolk, Maria Brandén, Bo Malmberg,,and Gunnar Andersson (2020) “Socio-demographic risk factors of COVID-19 deaths in Sweden: A nationwide register study”  Nature Communications, 11: (5097)

Barclay, Kieron, Anna Baranowska-Rataj, Martin Kolk, and Anneli Ivarsson (2020) “Interpregnancy Intervals and Perinatal and Child Health in Sweden: A Comparison Within Families and Across Social Groups” Population Studies, 74(3): 363-378                                   

Kolk, Martin and Gunnar Andersson (2020) “Two Decades of Same-sex Marriage in Sweden. A Demographic Account of Developments in Marriage, Childbearing and Divorce” Demography, 57(1): 147-169

Bernard, Aude and Martin Kolk (2020) “Why are young Swedes moving more? A cohort analysis of internal migration by move order” European Journal of Population, 36: 601-615

Morosow, Kathrin and Martin Kolk (2020) “How does Birth Order and Number of Siblings Effect Fertility? A Within-Family Comparison using Swedish Register Data” European Journal of Population, 36: 197-233

Li, Chun-Hao, Martin Kolk, Wen-Shan Yang, and Ying-Chang Chuang (2020) “Uxorilocal Marriage as a Strategy for Heirship in a Patrilineal Society: Evidence from Household Registers in Early 20th-Century Taiwan”, History of the Family, 25(1): 22-45

Kolk, Martin (2019) “Period and Cohort Measures of Internal Migration” Population, 74(3): 333-348

Molitoris, Joseph, Kieron Barclay, and Martin Kolk (2019) “When Birth Spacing Does and Does Not Matter for Child Survival: An International Comparison using the DHS” Demography, 56(4): 1349-1370

Kolk, Martin and Kieron Barclay (2019) “Cognitive ability and fertility amongst Swedish men born 1951-1967. Evidence from military conscription registers” Proceedings of the Royal Society B, 286 (1902): 20190359Barclay, Kieron and Martin

Kolk (2019) “Parity and Mortality: An Examination of Different Explanatory Mechanisms Using Data on Biological and Adoptive Parents” European Journal of Population, 35(1): 63-85

Kolk, Martin (2019) “Weak support for a U-shaped pattern between societal gender equality and fertility when comparing societies across time” Demographic Research, 40: 27-48


Recent Working papers

Kolk, Martin, Lucas Tilley, Emma von Essen, Ylva Moberg, Ian Burn (2023) ”Demographic Trends in Sweden's Transgender Population (1973–2020)” SSRN, 4427508

Eriksson, Helen and Martin Kolk (2022) ”Parental union dissolution and the gender revolution” Stockholm Research Reports in Demography. 2022:13

Alburez-Gutierrez, Diego, Nicola Barban, Hal Caswell, Martin Kolk, Rachel Margolis, Emily Smith-Greenaway, Xi Song, Ashton Verdery, Emilio Zagheni. (2022) . “Kinship, Demography, and Inequality: Review and Key Areas for Future Development.” SocArXiv. doi:10.31235/

Qi, Haodong and Martin Kolk. (2022) “How Does University Education Pay Off? – A Longitudinal Analysis of Life-Cycle Earnings” submitted manuscript


Doctoral thesis:

Kolk, Martin (2014) Multigenerational processes in demography. Stockholm University: Stockholm.