Seong Woo Lee

Immigrant trajectories into homeownership: a temporal analysis of residential assimilation.

Homeownership is an important symbol of a middle-class standard of living and residential assimilation in the United States. This study explores the rate of advancement into homeownership of immigrants, relative to native borns, in Southern California, a principal region of immigrant settlement. Application of a double cohort method enables longitudinal trends for immigrants, due to both aging and assimilation, to be distinguished from the cohort levels observable by cross-sectional techniques. Recent immigrants as well as young native borns are newcomers to the housing market and have lower attainment levels than earlier arrivals or older cohorts. Cohort trajectories are tracked from 1980 to 1990, adjusting for the influence of income, education, English proficiency, and marital status. Asian immigrants achieved extraordinarily high levels of homeownership soon after arrival, whereas Hispanic immigrants demonstrated sustained advancement into homeownership from initially very low levels.

Immigration cohorts and residential overcrowding in southern California

To what degree do immigrants reduce their high rates of residential overcrowding with increasing length of residence in the United States? This question is addressed through the application of a “double cohort” method that nests birth cohorts within immigration cohorts. This method enables duration of immigration effects to be separated from aging effects as cohorts pass through life course phases, when family sizes may be growing or shrinking. The analysis finds that cohort trends differ sharply from the cross-sectional pattern observed at a single point in time. Cohorts’ growth in income is found to contribute substantially to the decline in overcrowding over time. Cohort trends among Hispanic immigrants, however, diverge from those among others, indicating much less decrease in overcrowding and even increases over certain age spans.

Trends in the prevalence of chronic kidney disease, other chronic diseases and health-related behaviors in an adult Korean population: data from the Korean National Health and Nutrition Examination Survey (KNHANES)

BACKGROUND Chronic kidney disease (CKD) is an increasing public health problem. However, there have been limited data on the trend of CKD prevalence, along with the changes of health-related behaviors and other chronic diseases in an adult Korean population. METHODS Data from the Korean National Health and Nutrition Examination Survey in 2005 and 2007 were analyzed. The study subjects comprised 8400 participants aged ≥ 20 years with creatinine data. CKD was defined as estimated glomerular filtration rate (GFR) <60 mL/min/1.73m(2). GFR was estimated by the abbreviated Modification of Diet in Renal Disease equation. RESULTS The CKD prevalence was significantly decreased from 2005 to 2007 (8.8 versus 7.2%; P = 0.010). The prevalence of hypertension was stable but that of diabetes was increased. The proportion of blood pressure (BP) <130/80 mmHg in the whole population, and HbA1c <7% in the diabetic participants was increased from 2005 to 2007. Participants in 2007 walked more than those in 2005. The proportion of current smoking and sodium/energy/protein excess was decreased from 2005 to 2007. In subgroup analysis, only hypertensive participants without diabetes revealed a decreasing trend of CKD. CONCLUSIONS The CKD prevalence was decreased from 2005 to 2007. Since increased diabetes and improved diabetic control neutralized their impact on CKD, improved BP was the fundamental reason for the decrease. Various health-related behaviors may have indirectly affected the decrease of CKD through their effect in controlling BP and diabetes.

Single-Port Laparoscopic Appendectomy: Comparison with Conventional Laparoscopic Appendectomy

BACKGROUND Laparoscopic appendectomy is becoming popular for the treatment of acute appendicitis. Since it was first described, laparoscopic appendectomy has been modified various times for reducing pain and improving cosmetic results. Single-port laparoscopic appendectomy (SPLA) may reduce more postoperative trauma and obtain reliable cosmetic results. We compared the safety and feasibility of this technique with those of conventional laparoscopic appendectomy (CLA). SUBJECTS AND METHODS Between November 2008 and July 2009, 104 patients were enrolled in this study. Their diagnoses were performed by computed tomography scan. The demographic findings and surgical outcomes such as operation time, pathology, postoperative pain score, hospital stay, and complications of the SPLA group were analyzed and compared with those of the CLA group. RESULTS SPLA was completed in 42 patients, and 62 patients underwent CLA. Mean age was 29.9 years in the CLA group and 23.9 years in the SPLA group. The average body mass index of patients was 23.0 kg/m(2) in the CLA group and 20.5 kg/m(2) in the SPLA group. Mean operation time was 55.8 minutes in the CLA group and 51.7 minutes in the SPLA group. There was no conversion to open appendectomy in both groups. No major complications were encountered in the two groups. The mean postoperative hospital stay was 2.9 days for the CLA group and 2.6 days for the SPLA group. There were no deaths in either group. CONCLUSION SPLA is a safe technique and shows excellent cosmetic results. This is an easy procedure for an experienced laparoscopic surgeon even with conventional laparoscopic instruments. It remains to be evaluated in cases of perforated appendicitis and periappendiceal abscess.

Local housing-market effects on tenure choice

The main objective of thepresent study is to find out which marketfactors affect homeownership attainment aftercontrolling for individual human capital. The1980 and 1990 individual Census data (PUMS) inthe U.S. are used to investigate the contextualinfluences on choosing two types of housing:single- and multi-family housing. Trichotomoustenure choice models are applied to fourrepresentative age groups. The study takesadvantage of the multi-level design, allowingrelationships between individual and housingmarket characteristics to vary from place toplace. One finding is that market variations aswell as individual characteristics affecttenure choices. The authors argue that researchon homeownership attainment should not onlyconsider individual or household attributes butshould be sensitive to spatiality thatrecognizes market effects. The conclusion isthat housing research needs to be comprehensiveenough to understand the complex interactionbetween the individuals human capital and themetropolitan housing-market characteristics.

Linked and Independent African American Migration from Los Angeles

This paper examines African American migration from Los Angeles County, 1985–1990, utilizing Census Public Use Microdata Samples (PUMS) data to identify linkages between Los Angeles migrants and others in destination households. Increased migration to suburban counties and to regions outside of the South, since 1975–1980, suggests an overall diversification of African American migration. The majority of outmigrants were “independent” because they moved into 1990 destination households that contained only migrants from the same origin, Los Angeles County. Others were linked either to nonmovers or to migrants from other places in destination households. A discriminant analysis suggests that many migrants linked to nonmigrants were moving for assistance, depending on others at the destination for housing and financial resources. In contrast, independent migrants have the personal resources to set up their own destination households.

Constraints of Housing Age and Migration on Residential Mobility

This paper investigates the role of housing age in constraining residential mobility, measured as the percent of households that have moved into their homes in the past 15 months. The leading explanation for why mobility rates differ so much among regions of the United States has been the overall level of growth. The present analysis shows that the growth effect operates through both the newness of population (migration) and the newness of housing available for occupancy by all local residents. The posited explanation for this housing age effect is that progressively older units contain increasingly settled occupants, yielding fewer opportunities for in-movers in areas with older housing. It is empirically demonstrated that households in older housing have lower likelihood of recent mobility even after controlling for age, tenure, migration status, and state location of residence. The analysis reveals the temporal interdependency of mobility, migration, person age, and housing age.

An Econometric Model of Homeownership: Single-Family and Multifamily Housing Option

The purpose of this study was to examine the utility of the multifamily housing sector through models of household tenure decision, by comparing the various individual and market characteristics. We utilized individual household-level census data in the United States to detect different responses between single-family housing occupiers and multifamily housing occupiers during the 1980s. We found that although the investment potential for multifamily housing was almost equivalent to that of single-family housing in 1980, multifamily structures had lost their potential by 1990. Given this change, individual households choose multifamily housing as their shelter in a market where housing prices are high. This confirms the hypothesis that, if housing prices rise rapidly in a certain location, then individual consumers who cannot afford single-family housing may try to find a new alternative that meets their financial or other household-specific requirements.