The Research Page of Christopher Steven Marcum

Dissertation Research

My dissertation research focuses on structural explanations of age-differences in daily social interaction. I use the American Time Use Survey∞ to model patterns of who interacts with whom, doing what, at what time, and how long, in an average day. This "snapshot" approach to social network research allows for in-depth analysis of how personal networks are used in an everyday context. My emphasis for this research is on how American's personal networks differ across the life course, and especially by age group. My dissertation research sheds light on the processes by which age differences in social behavior arise.

A couple of illustrations from my dissertation research are provided below.

Comparing Age Differences in Diurnal Activity Sequences
This figure illustrates differences in the activity sequences from 2000 randomly selected individuals over the course of a single day in two age groups: 25-34 year olds to those age 75 and older. Each row in the figure represents one individual and each colored bar represents an activity spell. The matrix that the figure represents is sorted by Hamming distance∞, with more similarly clustered activity sequences closer together and more distant ones further apart. The figure clearly shows that the younger group has greater activity heterogeneity in both the types of activities and the order in which they are done, than the older group. In particular, and as expected, domestic and work production activities are replaced by sleeping and leisure activities moving from 25-34 to the 75 and up groups.

Social Time with Select Relations (in Hours) by Age
The average number of hours spent with different types of people and time spent alone is plotted against age, with 95% probability bands, in this figure. The figure illustrates how older people spend less time with others overall, and more time alone. Time spent with children declines after middle-adult and continues on a downward trajectory through old-age, while time spent with other relatives (non-spousal, non-children relatives) flatlines at about 2 hours in an average day by the late 20s. The irregular M-shaped curve of spousal time is so-shaped due to an increase in divorces in middle-adulthood followed by widowhood in very old age. Clearly, there is great variability in the amount of time people spend with different types of relations across the life course.

Other Research

In addition to my dissertation, I have a number of other research interests. Briefly, I have worked on projects related to organizational collaboration networks, population-level attitudinal change, and statistical research methods.

Posters

Here are few of the scientific posters I have presented at conferences over the past two years.

	Attachment	Size	Date Added
	paa2009.pdf	136.82 KB	7/29/2010 7:48 pm
	muri2009.pdf	704.48 KB	7/29/2010 7:51 pm
	paa2010.pdf	788.76 KB	7/29/2010 7:51 pm
	hazards2010.pdf	259.77 KB	7/29/2010 7:51 pm

Collaborators

I work closely, or have written papers, with UCI professors (in alphabetical order) Susan K. Brown, Carter T. Butts∞, Andrew Noymer∞, Joy E. Pixley∞, and Judith Treas∞. I have also collaborated with other graduate students, including (in alphabetical order) Ryan Acton∞ (UCI), Christine Bevc∞ (Univ. Colorado), Lorien Jasny∞ (UCI), and Daniel Schneider∞ (Princeton).

Curriculum Vitae

pdf version∞ html version∞

Resources

There are a number of research resources I use to stay productive. These include: R∞ for statistical computing; Latex∞ for document typesetting; and subversion∞ and rsync∞ for archiving and organizing my digital files. For the most part, I try to maintain a library of software that is open-source and free.