,Table of Contents page
1 Introduction 2
1.1 Theory 22019-
2020
2 Data description 3
3 Empirical analysis 4
3.1 Bivariate model 4
What is the impact of
the household monthly
net income on the
number of doctor visits
in Germany?
1
, 3.2 Multivariate model 5
3.2.1 Regression parameters 5
3.2.2 R-squared 5
3.2.3 Correlation among regressors 5
3.2.4 Assumptions for unbiased estimators 6
3.3 Statistical significance 7
3.3.1 T-test 7
3.3.2 P-value 8
3.3.3 Confidence interval 8
3.4 F-test 9
3.4.1 Economic significance 9
3.5 OVB 10
3.6 Specification 11
3.6.1 Chow test 11
3.7 Multicollinearity 13
3.8 Breusch-pagan test for heteroskedasticity 14
3.9 Reconsider your specification 15
3.9.1 Interaction term 15
3.9.2 Quadratic term 15
3.9.3 Rescaling our variables 15
3.10 Dependent variable in logs or levels 17
3.10.1 The bivariate log-log model 17
3.10.2 he multivariate log-log model 17
3.10.3 Dummy variables 17
4 Conclusion 19
5 Appendix 20
6 References 31
Introduction
Since the 1970s, inequality has risen sharply in most advanced countries around the world.
The income inequalities are getting higher and higher and are leading to health care inequalities.
Research has found that the higher your income, the better your health. But this is not strange if
you just do not have enough money to pay for your insurance or to pay for the additional health
costs. The most affluent 1% of men lived 15 years longer than the poorest 1%. Life expectancy for
2
, poor women was 10 years shorter compared to rich women. Inequality seems to be worsening
structurally between 1979 and 2007. This inequality makes it hard for the poorer population to
have the same access to health care as the top income. People with a higher income are more likely
to visit the doctor because they simply have enough money to pay for it. What is the impact of
individual income on the number of doctor visits in Germany? In this project we will discuss the
impact of household net income and education level on the number of doctor visits on the basis of a
model.
To start with, the paper is going to examine the basic relationship between the main
independent variable income and the main dependent one, doctor visits. Income is expected to have
a positive effect on doctor visits meaning that β1 should have a positive sign, because when people
have a larger income it permits them to spend more money on healthy living. Theory results show
that there is a negative correlation between health and low income, so there is a lot of inequality
between income groups and the access to health care. Furthermore, there are many articles and
projects gone upfront ours, reading more about in the theory part of our project.
Theory
In Germany, social health insurance is mandatory for all employed workers. During a year,
68% of people who have a health insurance visit the doctor once (C. Altenstetter, 2003). These
doctor visits are influenced by a lot of variables. We now take a closer look at the theory behind the
relationship of our dependent variable, doctor visits and major two independent variables; the
household monthly net income and education.
There are some studies that have focused on the effect of the income of people and how
often they visit the doctor in Germany. For example, an article called ‘incentive effects in demand for
health’ concludes that Households net income appears to be negatively correlated with health care
utilization (Riphahn et al., 2003). People who are unemployed, retired or are housewives have a
greater need for care. There is a negative correlation between health and low income (Riphahn et
al., 2003). So, health care use is unequally distributed between income groups. Over all European
countries, the need for the doctor and the use of such care are more concentrated among the poorer
population segments (Doorslaer et al., 2004). Moreover, poor people often easier repeat doctor
visits. The reason for this is pro-poor discrimination by the doctor, who apparently ask the poor
citizen to come back several times (Doorslaer et al., 2004).
People in the poor income segment are social disadvantaged, have a lower education and
generally a higher unemployment rate. When we look closer at our second independent variable
education, we see that low education leads to less knowledge about how to live a healthy life and
will lead to more doctor visits.
On average, people with a low education level, can expect to live two to five years less than
higher educated Europeans (Avendano, et al., 2009). Moreover, having a low education level is
associated with less income. So, the independent variables at least partly overlap. However, the
relationship between educational level and healthcare utilization is different across regions
according to an article: ‘Educational level and changes in health across Europe’ in the Journal of
European Social Policy 2009. In Northern Europe, low educational level is associated with fewer
doctor visits. In contrast, there is no association between education and doctor visits in Western
3
1 Introduction 2
1.1 Theory 22019-
2020
2 Data description 3
3 Empirical analysis 4
3.1 Bivariate model 4
What is the impact of
the household monthly
net income on the
number of doctor visits
in Germany?
1
, 3.2 Multivariate model 5
3.2.1 Regression parameters 5
3.2.2 R-squared 5
3.2.3 Correlation among regressors 5
3.2.4 Assumptions for unbiased estimators 6
3.3 Statistical significance 7
3.3.1 T-test 7
3.3.2 P-value 8
3.3.3 Confidence interval 8
3.4 F-test 9
3.4.1 Economic significance 9
3.5 OVB 10
3.6 Specification 11
3.6.1 Chow test 11
3.7 Multicollinearity 13
3.8 Breusch-pagan test for heteroskedasticity 14
3.9 Reconsider your specification 15
3.9.1 Interaction term 15
3.9.2 Quadratic term 15
3.9.3 Rescaling our variables 15
3.10 Dependent variable in logs or levels 17
3.10.1 The bivariate log-log model 17
3.10.2 he multivariate log-log model 17
3.10.3 Dummy variables 17
4 Conclusion 19
5 Appendix 20
6 References 31
Introduction
Since the 1970s, inequality has risen sharply in most advanced countries around the world.
The income inequalities are getting higher and higher and are leading to health care inequalities.
Research has found that the higher your income, the better your health. But this is not strange if
you just do not have enough money to pay for your insurance or to pay for the additional health
costs. The most affluent 1% of men lived 15 years longer than the poorest 1%. Life expectancy for
2
, poor women was 10 years shorter compared to rich women. Inequality seems to be worsening
structurally between 1979 and 2007. This inequality makes it hard for the poorer population to
have the same access to health care as the top income. People with a higher income are more likely
to visit the doctor because they simply have enough money to pay for it. What is the impact of
individual income on the number of doctor visits in Germany? In this project we will discuss the
impact of household net income and education level on the number of doctor visits on the basis of a
model.
To start with, the paper is going to examine the basic relationship between the main
independent variable income and the main dependent one, doctor visits. Income is expected to have
a positive effect on doctor visits meaning that β1 should have a positive sign, because when people
have a larger income it permits them to spend more money on healthy living. Theory results show
that there is a negative correlation between health and low income, so there is a lot of inequality
between income groups and the access to health care. Furthermore, there are many articles and
projects gone upfront ours, reading more about in the theory part of our project.
Theory
In Germany, social health insurance is mandatory for all employed workers. During a year,
68% of people who have a health insurance visit the doctor once (C. Altenstetter, 2003). These
doctor visits are influenced by a lot of variables. We now take a closer look at the theory behind the
relationship of our dependent variable, doctor visits and major two independent variables; the
household monthly net income and education.
There are some studies that have focused on the effect of the income of people and how
often they visit the doctor in Germany. For example, an article called ‘incentive effects in demand for
health’ concludes that Households net income appears to be negatively correlated with health care
utilization (Riphahn et al., 2003). People who are unemployed, retired or are housewives have a
greater need for care. There is a negative correlation between health and low income (Riphahn et
al., 2003). So, health care use is unequally distributed between income groups. Over all European
countries, the need for the doctor and the use of such care are more concentrated among the poorer
population segments (Doorslaer et al., 2004). Moreover, poor people often easier repeat doctor
visits. The reason for this is pro-poor discrimination by the doctor, who apparently ask the poor
citizen to come back several times (Doorslaer et al., 2004).
People in the poor income segment are social disadvantaged, have a lower education and
generally a higher unemployment rate. When we look closer at our second independent variable
education, we see that low education leads to less knowledge about how to live a healthy life and
will lead to more doctor visits.
On average, people with a low education level, can expect to live two to five years less than
higher educated Europeans (Avendano, et al., 2009). Moreover, having a low education level is
associated with less income. So, the independent variables at least partly overlap. However, the
relationship between educational level and healthcare utilization is different across regions
according to an article: ‘Educational level and changes in health across Europe’ in the Journal of
European Social Policy 2009. In Northern Europe, low educational level is associated with fewer
doctor visits. In contrast, there is no association between education and doctor visits in Western
3
