Essay 2 uses Chinese adult twin data to investigate birth weight effect, the outcomes of which have been changed to long-term achievements. The OLS results suggest that birth weight has significant positive relationship with earnings, adult height, and health conditions. However, within-twin-pair results indicate that birth weight has significant positive influence only on adult height. Essay 2 also systematically interprets the pattern of bias directions of OLS relative to within-twins estimates across empirical studies on long-term outcomes. For health measures, OLS estimates are consistently biased upward relative to within-twins estimates across empirical studies, suggesting an overall positive correlation between omitted factors and birth weight. On the contrary, the bias direction of OLS relative to within-twins estimates fluctuates across empirical studies on ability-related outcomes, including educational attainment and earnings. This suggests that there are two main types of omitted variable (e.g., endowments and post-birth parental inputs) with each type having different correlation with birth weight. / Essay 3 uses data from the 2000 and 2005 censuses of China. It analyzes trends on the marital behavior of Chinese people during 1970-2004, and the impact of the one-child policy in terms of marriage age, marriage rate, and assortative mating on age. First, this essay finds that from 1990 onwards, more people have preferred to marry at and after their mid-twenties. Interestingly, up to the early 2000s, the prevailing marriage rates of men and women over 35 years old maintained at very high levels (over 90%) despite China becoming more prosperous. Moreover, the positive assortative mating on age was more or less the same from 1970 to 2004. In addition, this essay is the first to compare the marriages of Zhuang people relative to other non-Han people (excluding Man people) around 1989 to implement the difference-indifferences (DiD) estimation. Results from DiD estimations indicate that the one-child policy encourages more people to delay marriages. On the one hand, the policy favors more men at 30 years old or above to marry young women in their twenties. On the other hand, interestingly, it also induces more young men to marry older women. / The dissertation consists of three empirical studies on Chinese household behavior. Essay 1 uses Chinese child twin data to examine the effect of birth weight on performances during childhood and adolescent periods. Essay 1 has three main contributions to literature. First, this essay is the first to use twin data of an Asian developing country to study the birth weight impact. Within-twins results suggest that birth weight has significant effect on physical growth, but no significant effect on school performance, health conditions, and personality. Second, this study is the first to apply threshold regression on twin data to examine the non-linearity effect of birth weight. Overall, there is no evidence to support the argument that the effect is nonlinear on medium-term outcomes. Third, this study is the first to test directly whether birth weight effect operates through interaction with post-birth parental inputs. There is no evidence to support that this mechanism works in within-twins results. / Wong, Man Kit. / Adviser: Junsen Zhang. / Source: Dissertation Abstracts International, Volume: 73-01, Section: A, page: . / Thesis (Ph.D.)--Chinese University of Hong Kong, 2010. / Includes bibliographical references. / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [201-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. Ann Arbor, MI : ProQuest dissertations and theses, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.