If the economy grows stronger, the number of new day-care workers will not be significantly greater than the number of day-care workers who move to better-paying jobs in other fields. If the economy grows stronger, most of the new jobs that are created will be in fields that pay well. The total number of young children in day-care centers will decrease if the cost of day care increases significantly. If the economy grows stronger, the number of workers employed by day-care centers is likely to decrease.
Economist: If the economy grows stronger, employment will increase, and hence more parents will need to find day care for their young children. Unfortunately, in a stronger economy many day-care workers will quit to take better-paying jobs in other fields. Ttherefore, a stronger economy is likely to make it much more difficult to find day care.
Which one of the following is an assumption the economist's argument requires?