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What are the effects of income on obesity rates?. Jaebong Kim ( JKQRC@umsl.edu ) University of Missouri – St. Louis Introduction to Policy Research, 2010 spring. Introduction. S. Korea has the lowest obesity rate among OECD country.
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What are the effects of income on obesity rates? Jaebong Kim (JKQRC@umsl.edu) University of Missouri – St. Louis Introduction to Policy Research, 2010 spring
Introduction • S. Korea has the lowest obesity rate among OECD country Figure 1. The percent of 15 years old who are obese (Source: OECD Health Data,2009) 31% of adults overweight Social Problem … 1
Background • Factors causing obesity Genetic Psychological factor Physical inactivity Culture High calorie diet Medical problems • Investigate relationship b/w income & obesity make recommendation to governors of Korea 2
Hypothesis / Methodology Ha: States of the United States with higher median household income will have lower obesity rates than states with lower median household income H0: There is no relationship between median household income and the obesity rates in the United States • cross-sectional Quasi-Experimental design • unit of analysis : state of U.S. 3
Dependent Variable • Dependent variable : state-level obesity rate • Defining obesity (Center for Disease Control) weight (lb) [height (in)] { } × • Body Mass Index = 703 2 4
Dependent Variable (cont’d) • Normally distributed Figure 2. Histogram of state-level obesity rate, 2008 (Source: CDC, n=50) 5
Independent Variable • Leading independent variable • : median household income Figure 3. Histogram of median household income of state, 2008 (Source: U.S. Census Bureau, n=50) • Normally distributed • - positively skewed 6
Independent Variable (cont’d) • Control variables Table 1. variables which have relationship with obesity rate of state in 2008 (Source: U.S. Census Bureau, CDC ) 7
Finding • Relationship Figure 4.Scatter plot with a fitted regression line for state obesity rate on the median household income of state in 2008. (Source: U.S. Census bureau, CDC) 8
Finding (cont’d) • bivariate regression Table 2. The result of bivariate regression for obesity rate on the median household income of state in 2008. (Source: U.S. Census bureau, CDC) * p<0.05 9
Finding (cont’d) • Correlation of independent variables • Table 3.Correlation of variables which have relationship with obesity rate of states • in 2008. (Source: U.S. Census bureau, CDC) 10
Finding (cont’d) • multiple regression Table 4. The result of multiple regression of state obesity rate as the dependent variable on three independent variables in 2008. (Source: U.S. Census bureau, CDC) * p<0.05 11
Conclusion • Accept Ha Median household income Obesity rate • Why Lower-income people have fewer grocery store and less access to affordable fruits and vegetables (Jeffry Levi) They consume low-price high-calorie foods because of the high price of fruits and vegetables. (Neil Gandal) 12
To foster consuming fruits/vegetables Recommendation To improve accessibility to grocery Encourage grocery store owners to open their store in the area of lower-income neighborhoods with incentive program such as tax exemption benefit Implement “Grocery Voucher Program” - only for grocery (alcohol & cigarettes are not permitted) 13