Ka-Yuet Liu

Associate Professor, UCLA Sociology

I'm interested in the social and spatial aspects of epidemiological networks.

Bio


I'm an Associate Professor in the Department of Sociology, UCLA. I received my D.Phil. (Sociology) in 2008 from the University of Oxford. Then I worked as a post-doc on the Understanding Autism Project (PI: Peter Bearman) at Columbia University in New York. I joined UCLA as a faculty member in 2012.

My research mostly focuses on the intersections between social network analysis and social epidemiology. My major test cases are the diffusion of health conditions that people don't typically associate with network processes. I ask questions such as: under what circumstances suicides can have a large rippling effect? What are the roles of knowledge diffusion in the rising prevalence of autism? Using these cases, I demonstrate how paying attention to social networks can help us understand puzzling epidemiological patterns that cannot be readily explained by shifts in biological risks.

My work has appeared in American Journal of Sociology, Demography, Social Forces, International Journal of Epidemiology, Health and Space, and other journals. My research has been supported by grants from the National Institute of Health. I'm the lead author of the paper that received the Eliot Freidson Outstanding Publication Award in 2011.


Projects

On autism:

How can the prevalence of autism, a disorder supposedly largely determined by genetics, increase so rapidly? We are the first show that genetics have a less important role in Autism than we thought. What we found is that social Influence has a substantial role in explaining the rising prevalence of autism: living nearby other children with autism increases the chance of an autism diagnosis (but not completing diagnoses), and we argue it is due to the diffusion of knowledge. The spatial patterns of autism are also pointing to social drivers. Our population-wide agent-based model that incorporates network processes uniquely predicts the location of autism clusters.

On suicide:

How do our our social networks affect our suicide risks? Apart from the better known impact of social support, whom your neighbors also matters, and the effect is not always positive.

When would a suicide have an unexpected rippling effect? Our work has shown that suicides of colleagues have unexpectedly large network effects. The diffusion of a suicide method can substantially increase suicide rates.

Work in Progress

determinants and consequences of vaccine refusals (with Ashley Gromis)

  • spatial analysis

  • large-scale agent-based model

immigration and mortality

  • legal status and unnatural causes of deaths

  • natural causes and age of death (with Josefina Morales)

  • suicide rates by country of origin (with Zhenxiang Chen)

the rise of obstetric interventions

  • funded by an R01 grant from NIHCD (PI: Julien Teitler & Nancy Reichman)

  • diffusion and network models

Papers

  1. Gromis, A. & Liu Ka Y. (2020). The emergence of spatial clustering in medical vaccine exemptions following California Senate Bill 277, 2015-2018. American Journal of Public Health, 110, 1084-1091

  2. Gromis, A. & Liu Ka Y. (2018). The Roles of Autism Prevalence and Neighborhood Composition on Vaccination Exemption Pockets: A Population-wide Study. Vaccine 36(46):7064-7071

  3. Taschereau-Dumouchel, V., Liu, Ka Y., Lau, H. (2018). Unconscious psychological treatments for physiological survival circuits. Current Opinion in Behavioral Sciences 24: 62-68

  4. Chen, Z. & Liu, Ka Y. (2018). Assimilation of China’s rural-to-urban migrants: A multidimensional process. Chinese Journal of Sociology, 2057150X18764232.

  5. Miuccio M, Liu, Ka Y., Lau H; Peters M (2017). Six-fold over-representation of graduates from prestigious universities does not necessitate un-meritocratic selection in the faculty hiring process. Plos One, 12(10) e0185900.

  6. Liu, Ka Y(2017). To compare is to despair? A population-wide study of neighborhood compositions and suicide in Stockholm. Social Problems, 64(1)532-557).

  7. Cheslack-Postava, K, Susser, E, Liu, Ka Y, Bearman, P (2015). Can sibling sex ratios be used as a valid test for the prenatal androgen hypothesis of autism spectrum disorders? PlosOne, e0141338

  8. Makovi, K, Winter, A, Liu, Ka Y, Bearman, P (2015). The population level impacts of differential fertility behavior of parents of children with autism. Sociological Science 2:398-419

  9. Liu, Ka Y, Bearman, PS (2015). Focal points, endogenous processes and exogenous shocks in the autism epidemic. Sociological Methods and Research, 44(2) 272-305.

  10. McCurdy, LY, Maniscalco, B, Metcalfe, J, Liu, Ka Y, de Lange, FP, Lau, H (2013). Anatomical coupling between distinct metacognitive systems for memory and visual perception. The Journal of Neuroscience 33(5): 1897-1906.

  11. Mazumdar, S, Winter, A, Liu, Ka Y, Bearman P (2013). Spatial clusters of autism births and diagnoses point to contextual drivers of increased prevalence. Social Science & Medicine, 95, 87-96

  12. Mazumdar S, Liu Ka Y, Susser E, Bearman P (2012). The disappearing seasonality of autism conceptions in California. PLos One 7(7)e41265

  13. Keyes, K, Susser, E, Cheslack-Postava, K, Fountain, C, Liu, Ka Y, Bearman, P (2012). Cohort effects explain the increase in autism diagnosis among children born from 1992 to 2003 in California. International Journal of Epidemiology, 41(2):495-503

  14. Cheslack-Postava K, Liu Ka Y, Bearman P (2011) Closely spaced pregnancies are associated with increased odds of autism in California sibling births. Pediatrics 147(2): 127:246–253

  15. Yip, PS, Yip PS, Hawton K, Liu Ka Y, Liu KS, Ng PW, Kam PM, Law YW, Wong TW (2011). A study of deliberate self-harm and its repetition among patients presenting to an emergency department. Crisis 32(4): 217-224.

  16. Liu Ka Y, King M, Bearman P (2010) Social influence and the autism epidemic. American Journal of Sociology 115(5): 1387–1434

  17. Liu Ka Y, Zerubavel N, Bearman P (2010) Social demographic change and autism. Demography 47(2):327–343.

  18. Mazumdar, S, King, M., Liu, Ka Y, Zerubavel, N, Bearman, P (2009) The spatial structure of autism in California, 1992-2001. Health and Place 16: 539-546

  19. Liu, Ka Y (2009). Suicide Rates in the World: 1950-2004. Suicide and Life-Threatening Behavior. 39(2):204-13.

  20. Liu, Ka Y, Chen, E, Cheung A, Yip PSF (2009) Psychiatric history modifies the gender ratio of suicide rates. Social Psychiatry and Psychiatric Epidemiology 44(2):130-4

  21. Chan W, Law CK, Liu Ka Y, Wong P, Law YW, Yip PSF (2009) Suicidality in Chinese adolescents: the role of family and cultural influences. Social Psychiatry and Psychiatric Epidemiology. 44:278–284.

  22. Hedström, P, Liu, Ka Y, Nordvik, M (2008) Interaction domains and suicides: A population-based panel study of suicides in Stockholm, 1991-1999. Social Forces 87(2):713-740.

  23. Cheung M, Wong P, Liu Ka Y, Yip PSF, Fan S, Lam TH (2008) A study of sexual satisfaction and frequency of sex among Hong Kong Chinese couples. Journal of Sex Research 45: 129-39

  24. Liu Ka Y, Beautrais A, Caine E, Chan K, Chao A, Conwell Y Law C Lee D, Li P, Yip SF (2007) Charcoal burning suicides in Hong Kong and urban Taiwan – An illustration of the impact of a novel method of suicide on overall regional rates. Journal of Epidemiology and Community Health 61:248-53

  25. Fu KW, Liu Ka Y, Yip PSF (2007) Predictive validity of the Chinese version of the Adult Suicidal Ideation Questionnaire: psychometric properties and its short version. Psychological Assessment 19:422:9

  26. Cheung YB, Liu Ka Y, Yip PSF (2007) Performance of the CES-D and its short forms in predicting suicidality. Suicide and Life-Threatening Behavior, 37:79-88

  27. Chen EYH, Chan W, Chan S, Liu Ka Y, Chan C, Wong P, Law W, Yip P (2007) A cluster analysis of the circumstances of deaths in suicides in Hong Kong. Suicide and Life-Threatening Behavior 37: 576-84

  28. Liu, Ka Y, Chen E, Chan, C, Lee TS, Law YW, Yeates C, Yip PSF (2006). Socio-economic and psychological correlates of suicidality among Hong Kong working-age adults: results from a population-based survey. Psychological Medicine 36: 1759-68

  29. Chen EYH, Chan W, Paul W, Chan SSM, Chan CLW, Law YW, Beh PSL, Chan KK, Cheng JWY, Liu Ka Y, Yip PSF (2006) Suicide in Hong Kong: a case-controlled psychological autopsy study. Psychological Medicine 36:815-25.

  30. Cheung YB, Law CK, Chan, B, Liu Ka Y, Yip PSF (2006) Suicidal ideation and suicidal attempts in a population-based study of Chinese people: Risk attributable to hopelessness, depression, and social factors. Journal of Affective Disorders 90:193-6.

  31. Yip PSF, Liu Ka Y (2006) The Ecological fallacy of gender ratio of suicide in China. British Journal of Psychiatry 189: 465-6

  32. Yip PS, Liu Ka Y, Hu J, Song XM (2005) Suicide rates in China during a decade of rapid social changes. Social Psychiatry and Psychiatric Epidemiology 40:792-8

  33. Yip PSF, Liu Ka Y, Law CK, Law YW (2005) Social and economic burden of suicides in Hong Kong SAR: a year of life lost perspective. Crisis 26:156-9.

Yip PSF, Liu Ka Y, Lam TH, Stewart SM, Chen E, Fan S (2004) Suicidality among high school students in Hong Kong. Suicide and Life-Threatening Behavior 34:284-93.

Teaching

courses I taught at UCLA

Quantitative Methods

  • Intermediate Statistical Methods (sociol 210B)

  • Quantitative data analysis (sociol 212A)

Network analysis

  • Social Networks (sociol 111)

  • Seminar on Social Networks & Health (sociol 191V)

  • Seminar on Social Networks and Health (sociol 191V)

Contact

E-mail: ka at soc dot ucla dot edu | 264 Haines Hall, 375 Portola Plaza, Los Angeles, CA 90095 |Tel: 310-267-4967