Week 13 Application! DPPG 8504 Sara Spowart, PhD, MPA

Today’s Agenda Pop-quiz Multiple Regression Scenario Dummy Coding Scenario

Regression Line (I will NOT ask you to calculate this outside of R Commander*) The Regression Line With one independent variable, we may write the regression equation as: Y is an observed score on the dependent variable a is the intercept b is the slope X is the observed score on the independent variable e is an error or residual We can extend this to any number of independent variables: Note: If you want to calculate by hand the equations are here at:

Regression Line For OUR purposes I want you to be able to say: Y= a + b 1 Education 1 + b 2 Safety 2 + b 3 Relaxation 3 + error This is just a ‘statistical sentence’ to indicate which independent variables you have selected to predict Y. That is the main significance of it here This statistical sentence means: “Y” is predicted by the independent variables “Education,” “Safety” and “Relaxation”

Multiple Regression Activity Please download the “Country Data” from the class website under week 13 Calculate Multiple Regression 3 times HDI= Y & Fertility and GDP = X 1 and X 2 Fertility = Y & HDI and GDP = X 1 and X 2 GDP = Y & Fertility and HDI= X 1 and X 2 1) Write ‘statistical sentences’ for the statistically significant relationships 2) Interpretation of slope coefficients: For every 1 unit increase in X i, Y increases/decreases by b i, holding other factors in the model constant* (Please memorize this)

Multiple Regression Activity Here: Y= HDI and Fertility X 1 and GDP X 2 1) First, look at overall p-value=.01 <.05 so reject the null 2) Second, GDP (X 2 ) is predictive of HDI (Y) here 3) Third, describe the relationship of GDP to HDI. For every 1 unit increase in GDP, HDI increases by , holding fertility constant.*

Multiple Regression Activity Here: Y= GDP and Fertility X 1 and HDI X 2 1) First, look at overall p-value=.02 <.05 so reject the null 2) Second, HDI (X 2 ) is predictive of GDP (Y) here 3) Third, describe the relationship of HDI to GDP. For every 1 unit increase in HDI, GDP increases by 5804 billion dollars, holding fertility constant.*

Multiple Regression Activity Here: Y= GDP and Fertility X 1 and HDI X 2 First look at overall p-value..464>.or so keep null

Survey Activity Please complete class activity listed under class materials in Week 13 Share findings with the class