Answer:
When things improve for the poor, people start imagining a better future, and no longer content with their lot, they want improvement faster than even a growing economy can deliver.
Step-by-step explanation:
This is often the case when an economy goes through periods of prosperity. When an economy is bad, the poor are often unhappy. However, they also tend to be used to their situation. However, when the economy improves, the poor are able to imagine how the economy might improve even more. As they imagine that a better future is possible, they become more discontent with their situation. Therefore, they become more likely to engage in a revolution.