Human decisions are simultaneously determined by economic incentives and psychological motivations. Based upon this fundamental assumption, I compose three interdisciplinary studies which analyze individual, collective and government actions at multiple levels of aggregation, and how they in turn lead to various economic and psychological outcomes. In the first study, Iexplore the key predictors of the level of compliance to social distancing and mask wearing in the United states by aggregating interdisciplinary datasets and applying multi-level analysis. I use a behavioral model to classify the determinants of compliance to COVID-19 response measures into economic incentives and psychological motivations and show that the former would have an increasing marginal effect on working hours. Empirically, I show that (a) economic vulnerability was the key predictor of failure of social distancing in 2020, even taking partisanship into account. (b) mask wearing was more politicized than social distancing, and in Fall (close to the elections), Republican partisanship was the only dominant indicator of noncompliance of mask wearing. In the second study, we use a coordination game model to discuss the dynamics of Non-Pharmaceutical Interventions (NPIs) on COVID-19 in the United States. We use atheoretical model to justify that there exist social reinforcement effects between policies in US states, i.e. the implementation of an NPI in a state would increase the possibility that others follow suit. Under certain conditions, if enough states engage in NPIs, they will tip others that have not yet done so to follow suit and thus shift the Nash equilibrium to the greatest one (allstates follow). Then, we show that there can be equilibria where states with different political leanings adopt different strategies when politics is a determinant of the interaction intensity. Empirically, we use a random utility model (RUM) to test it in reality with Probit and Logit regressions, and find robust evidence that inter-state social reinforcement is important and that equilibria can be tipped in mask wearing, and slightly weaker confirmation for social distancing. In the last study, I explore how personality traits in China are different from the traditional Five-Factor model by a large twin dataset in Yunnan Province. I find robust evidence about personality structures, formation and impacts in China and state three findings: (1) Personality traits in China seem to have a significance deviation from the well-accepted Five Factor Model. Instead, it has two general factors, relying on whether the item is positive or negative in tone. Positive factors include Social Desirability, Extraversion and Openness; negative factors include Disorderliness, Neuroticism and Introversion. (2) The genetic heritability of personality traits in China is significantly lower than that measured in the Western countries. For some traits, such as Social Desirability and Disorderliness, the genetic effect is around 0 and the shared environmental effect is much larger. This challenges previous findings in the West. (3) Using a within-twin fixed effect model, we find suggestive evidence on the causal effect on economic preferences and outcomes, including education performance, income, risk attitudes and subjective well-being.These three studies use the similar behavioral science methodology to study different levels of decision making, and all have important implications for issues of sustainable development.