This is an important question. Williamsburg is a great section of Brooklyn and recently it has seen some development. We can call this gentrification.
Gentrification changes the economy in several ways. First, more and more wealthier people move into the area. This means the prices of housing gets more expensive. For this reason, many of the poorer people get pushed out. They are no longer able to afford the housing. Often times, these poorer people are immigrant families.
Second, with this wealthier population, new businesses move in to support the new population. This is good for new businesses, but not so good for the older immigrant population. They often times are out of a job and cannot get jobs with these new businesses. So, this could provide an economic hardship.
In the end, poorer people get hurt and often times these are immigrants.