Increases in minimum wage levels improve the local economy, as people on minimum wages support local businesses with their extra income. Local shops, and service businesses benefit from those on the lowest income, having more disposable income. Minimum wage earners do not invest overseas, they do not purchase food from, housing or services from interstate. The extra money they earn, feeds directly into the local economy.
A boost in the local economy does indeed produce more employment. If local businesses are busier, they put on more staff.