The National Bureau of Economic Research (NBER) just released a new working paper, “School Competition and Teacher Labor Markets: Evidence from Charter School Entry in North Carolina” by C. Kirabo Jackson of Northwestern University.  Professor Jackson concluded,

I find that teachers moving from TPSs [traditional public schools] to charter schools have below-average qualifications, but contrary to common belief, schools that face increased charter school competition do not experience any long-run increases in teacher turnover. This suggests that charter schools merely provide alternative employment for less effective teachers who would have left TPS absent charter entry.

Charter schools are required to maintain a minimum percentage of state certified teachers, so it is no surprise that charters would draw teachers from local districts.  The fact that charters hire teachers with “below-average qualifications” may reflect the inexperience of the charter administrator, limitations of teacher supply, or both.  Regardless, Jackson found that charters do not drain district schools of teaching talent.

That is not to say that there is no effect.  Jackson explains,

I do however find evidence of competitive supply side pressure such that schools that face charter entry experience declines in the number of new teachers hired. I also find that schools that face charter entry increase teacher pay ? indicative of a demand side response to better attract and retain teachers. Consistent with these being the results of competitive pressure, I find that these effects are more pronounced in difficult to staff schools. I also found evidence of very slight declines in teacher quality associated with charter entry at these difficult to staff schools.

District schools are subject to the state salary schedule.  As such, I suspect that teacher pay increases are a product of hiring more experienced and/or more credentialed teachers, rather than the implementation of a merit or incentive pay system.  Moreover, a district school that sheds below-average teachers would experience a decline in teacher quality only if the replacement teachers were inferior to those who departed for the charter school.