The economists were asked about the statement

The main drawback to allowing all public school students to take the government money (local, state, federal) currently being spent on their own education and turning that money into vouchers that they could use towards covering the costs of any private school or public school of their choice (e.g. charter schools) would be that some students would not make an active choice and would be left with much worse peers and a weaker school.

78 percent either agreed or strongly agreed. Edward Lazear gave something close to my answer:

The main disadvantage to vouchers is potential weakening of public schools. But those that would lose students are terrible already.

What strikes me is that the overwhelming majority of these mainstream economists do not have confidence in the ability of people to choose for themselves. This may blunt one of the criticisms of economists, which is that they are too inclined to treat consumers as rational.