Economics, 3rd Edition

Graphs of a Single Variable

Three common graphs are shown in Figure 2A.2. The pie chart in panel (a) shows the proportion of gross 

domestic product devoted to investment in the so called ‘G7 countries’. These countries are Japan, 

the United States, United Kingdom, France, Germany, Canada and Italy. A slice of the pie represents 

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32  PART 1  INTRODUCTION TO ECONOMICS

Types of Graph

The pie chart in panel (a) shows the proportion of GDP devoted to investment in the G7 countries in 2011. The bar graph in panel (b) 

shows the interest rate set by the ECB. The time-series graph in panel (c) shows the unemployment rate for the 27 EU countries from 

2000–2011. Panel (d) shows the same information as panel (c) but uses a different scale for the vertical axis.