A natural experiment of the effect of advertising on sales: the SASOL case

China's so-called ‘reform and opening up’ policy (Gai Ge Kai Fang), implemented nearly 30 years ago, has led to tremendous economic development. China's nominal Gross Domestic Product (GDP) was 3.25 trillion US dollars in 2007, making it the fourth largest economy in the world. At the same time, income inequality has become quite skewed in China, inviting considerable criticism. Moreover, the trend towards greater income inequality persists. Of particular public policy relevance is the effect of income inequality on health disparities in China, particularly for low-income households. This study addresses this issue using a longitudinal dataset from the China Health and Nutrition Survey (CHNS) over the period 1997 to 2006. Our central finding is that income inequality affects health differently by socioeconomic status: income inequality harms individual health among low income households by more than it does among high income households. More specifically, health is more adversely affected by greater income inequality for households with low incomes. China's central government is committed to making further investments in the health care system. As part of that effort, attention should be directed at low income households to reduce health inequality, possibly providing them with a health insurance safety net similar to Medicaid in USA.