Based on the provided information, federal government purchases as a percentage of GDP have seen periods of both rise and fall since the 1950s, with defense spending decreasing and spending on Social Security and healthcare increasing over time. The most accurate answer to the question is (b) 'rose from the early 1950s until the mid 1980s, and then fell.'
Given the information provided, we can answer the student's question regarding federal government purchases as a percentage of GDP. The data indicates that federal spending has generally been between 18% to 22% of GDP since 1960, with fluctuations primarily due to changes in spending on defense, Social Security, healthcare, and interest payments. More specifically, defense spending has decreased as a percentage of GDP since the 1960s with notable increases during the 1980s and post-9/11 period, while spending on Social Security and healthcare has increased. The federal spending level even climbed above the usual 18-22% range during 2009 and 2020.
From the provided options, the closest match to these observations would be (b) 'rose from the early 1950s until the mid 1980s, and then fell.' This is because after the 1980s, despite the fluctuation, there has been a general trend of decline in defense spending which reduced the overall federal spending as a percentage of GDP.