Answer:
Between 1981 and 2001, the change most likely happening in the US economy was an increase in spending by consumers.
During this period, the US experienced significant economic growth and expansion, with rising incomes and consumer confidence. This led to increased consumer spending on goods and services, which fueled economic activity and stimulated further growth.
Additionally, factors such as advancements in technology, financial deregulation, and globalization contributed to increased consumer spending and overall economic prosperity during this timeframe.
Therefore, an increase in consumer spending is the change most likely happening in the US economy between 1981 and 2001.