Answer:
Dear U.S. president
As an economist, I personally agree with raising the minimum wage, 7 dollars an hour is very low, and does not reflect gains in worker's productivity.
However, raising it to 15 dollars an hour could be too high, since it would be higher than the minimum wage of the state of California, which is currently 14 dollars an hour, and California is one of the states with the highest cost of living.
For this reason, I propose raising the minimum wage to 10 dollars an hour, a moderate solution. This is a level that reflects workers' productivity better, at the time that protects many sectors of the economy from having to lay off workers due to a hike in labor costs.
Sincerely, random economist.