The following is an excerpt from the abstract of a recent journal article entitled “The Effects of Maternal Fasting during Ramadan on Birth and Adult Outcomes” by Almond and Mazumder (2007). Ramadan is the traditional month of daytime fasting by Muslims: “We use the Islamic holy month of Ramadan as a natural experiment for evaluating the short and long-term effects of fasting during pregnancy. Using Michigan natality data we show that in utero exposure to Ramadan among Arab births results in lower birthweight and reduced gestation length. Preconception exposure to Ramadan is also associated with fewer male births. Using Census data in Uganda we also find that Muslims who were born nine months after Ramadan are 22 percent (p = 0.02) more likely to be disabled as adults. Effects are found for vision, hearing, and especially for mental (or learning) disabilities.” 

a) : Describe how one or more theories discussed in lecture 4 might explain the findings by the authors. 

b) : Suppose that a scientific study determines that fasting during Ramadan actually has no causal effect on foetal health. What ‘other’ factor(s) could explain the Michigan results? Provide an argument (preferably with evidence) to establish the validity of your explanation.

Lecure 4 Socio-economic disparities in health

•Health Disparity: (def) differences in health --incidence, prevalence, mortality, and burden of disease -- between specific populations

- Example: death rates for all cancer types for

        both men and women are highest among    

        African Americans

•Ubiquitous worldwide across races, educational attainments, employment grades, and incomes

   - Broadly across all socioeconomic statuses (SES)

§By education:

- College graduates are 25% more likely to survive to age

       68 than high school dropouts

§ By race:

- Hispanics report better health status than black individuals

- White individuals report better health then both Hispanic

        and black individuals

- Health deteriorates with age across all races, but disparities persist

§Generally: high-income individuals self-report a higher health status than those of lower incomes

§For most conditions, the poor exhibit more incidences of disease

§Some exceptions like

•Bronchitis -- no difference

•Hay fever -- the rich appear to be diagnosed with hay

    fever more often

§May be explainable if richer children visit the doctor

    more often and hence, are more likely to be diagnosed

§Even in countries with universal health insurance, health disparities persist

§Canada:

- Self-reported health status for children at high SEC better than children of low SES (Currie and Stabile

   2003)

§England:

- We discuss the Whitehall studies later

Why do health disparities exist? Theories to explain health disparities

ØReasons/theories

- Early life events

- Income levels

- Stress of being poor

- Work capacity

- Impatience

- Adherence to medical advice

Ø Policy importance of understanding causes of disparities before addressing them

Hypotheses for health disparities

•Efficient producer

•Thrifty phenotype

•Direct income

•Allostatic load

•Income inequality

•Access to care

•Productive time

•Time preference (The Fuchs hypothesis)

The efficient producer hypothesis

•Hypothesis: better-educated individuals are more efficient producers of health than less well-educated individuals

- Grossman predicts that people who are more

       efficient health producers will have higher H*

•Lleras-Muney (2005) find that an additional year of schooling caused ~1.7 year increase in life expectancy in 1920s US

- Hence, education improves health

Possible causal mechanisms

•Possible reasons for positive correlation between health and education?

- Lessons in school help students to take better care of    themselves

- Schooling helps students be more patient               when it comes to payoffs of investments (like health)

- Better-educated more likely to adhere to

treatment regimens

Thrifty phenotype hypothesis

•Genetic reasons for being inefficient at producing health

•Deprivation of resources (food) in utero and early childhood leads to activation of “thrifty” genes that are useful for sparse environmental conditions

•These “thrifty” genes good for scarce environments but bad in conditions of abundance

•More likely to develop diabetes, obesity, and other disorders later in life

•Disparities arise because poorer individuals are more likely to have resource deprivation early in life

§Use natural experiments to test this hypothesis

- A randomized experiment that randomly deprived some

       children in utero and not others would be pretty unethical!

§Natural experiments use environmental shocks that naturally create control and treatment groups

- Examples: earthquakes, famine, snowstorms

§Good natural experiment eliminates selection bias

The direct income hypothesis

•Hypothesis: disparities exist because rich people have more resources to devote to health

•Rich individuals have an expanded PPF because of extra financial resources

•Expanded PPF = higher H* that can be obtained

Allostatic load hypothesis

•Hypothesis: Prolonged or repeated stress is unhealthy and can cause an increased rate of aging

•In the Grossman model, aging is represented by rate of depreciation of health capital δ

•High stress load leads to a higher δ

Income inequality hypothesis

§Hypothesis: Health disparities are caused by an unequal distribution of income

- Related to the allostatic load hypothesis

- More equal societies are less stressful and therefore healthier

Access to care hypothesis

§Hypothesis: Those with high incomes can afford more generous health insurance compared to those of low income

Productive time hypothesis

§SES differences are caused by disparities in health
   - Bad health leads to lower productive time and

therefore less time to produce income

§Oreopoulos et al. (2008) and Black et al. (2007) study siblings growing up in same household

- Those with worse health during infancy have

        higher mortality rates, lower educational

        achievement, and lower adult earnings

The Fuchs hypothesis

§Bad health does not cause low SES, and low SES does not cause bad health

- A third factor – time preference -- causes both!

§Health and SES both determined by the willingness to delay gratification

- People who are willing to delay gratification are more

          willing to invest in things like education and health

§People willing to delay gratification have a high discount factor δ