What is a charter school?

Charter schools are an increasingly popular alternative to traditional public schools.  

There are three types of charter schools created by the Texas Education Code.  They are all public schools.  Two exist solely within independent school districts (ISDs).  The third type is open enrollment charter schools.  These exist outside the ISDs.

Open enrollment charter schools are:

·  Tuition-free,

·  Non-selective (admission is by lottery or first-come/first-served), and

·  Open to families in a broad geographical area, often 10 or more ISDs.

Charters are known for having:

·  Less bureaucracy and red tape,

·  At-will employment, and

·  A high degree of accountability to parents.

Rather than being run directly by the government, open enrollment charter schools are 501c3 nonprofits that receive government funding, like most colleges.  By law, 501c3 nonprofits serve the public good, do not have owners, and do not accrue profit.  There is a merit-based selection process by which the State of Texas contracts with specific nonprofits to create charter schools.

WERe charter schools meant to be laboratories of innovation for traditional public SCHOOL districts?

Maybe somewhere, but not in Texas.  Texas charter schools were created by the legislature to accomplish five purposes:

1.  Improve student learning,

2.  Increase the choice of learning opportunities within the public school system,

3.  Create professional opportunities that will attract new teachers to the public school system,

4.  Establish a new form of accountability for public schools, and

5.  Encourage different and innovative learning methods.

See Texas Education Code § 12.001.  


overall charters do a better job of educating students and cost less.

The Texas charter law and, in fact, most charter laws across the country appear to create a better structure for improving educational outcomes than the traditional public school district.  Charters have simultaneously more freedom and more accountability to parents than districts that are government-run and guaranteed students.  Generally, we expect entrepreneurs in free markets to innovate, continuously improve, and lower costs in a way that government monopolies cannot.  The evidence suggests that it works this way in public education too.  

As the charter sector has grown, it has surpassed traditional public schools in educational outcomes.  This is true nationally, statewide, and in San Antonio in particular.  Given the better results and lower cost to taxpayers, charters are increasingly seen as a cost-effective answer to the education crisis.  

This would not be the case, of course, if charter growth hurt the academic progress of students who remain in traditional public schools.  Fortunately, this does not appear to be so.  A variety of studies addressing that question suggest that charter growth has either a positive secondary effect on the quality of traditional public school districts around them or no secondary effect at all.  Moreover, a national study of 13,000 districts has found that the bigger the charter sector, the greater the net improvement for educational quality in a city/district/town when you look at all public school students together, charter and traditional.  

The research does not yet explain why this happens; however, we speculate that competition for funding forces school boards and administrators to prioritize the concerns of families over the concerns of special interests, such as vendors and teachers unions, that tend to swing school board elections, and that this deference to families is fundamentally good for educational quality as measured by test scores.  Another possible cause for the positive charter effect on a region is an adoption of charter-born innovations and best practices by traditional public schools when employees move from charters to traditional public schools.  The more charter schools a city has and the better they are, the more this would happen.  


According to Stanford University’s Center for Research on Educational Outcomes (CREDO), in 2016-17 (the most recent data year), the average San Antonio charter student benefited by .09 standard deviations more academic growth annually in reading and .07 standard deviations more in math than they would have experienced in their traditional public school.  This is roughly equivalent to 53 extra days worth of educational progress every year in reading and 41 days in math.  Given that the school year consists of 180 days, we are talking about an extra 3.8 years worth of extra educational progress in reading and an extra 3 years in math over the course of a K-12 education, by virtue of attending a charter school in San Antonio.  Note that this is not a subset of the best charters.  This is a sector-wide average value-add. 

The charter sector's pattern of more educational progress holds true in all published subgroups as well, including males, females, black students, Hispanic student, English Language Learners, Special Education students, and student in poverty.

See CREDO, City Study 2019: San Antonio.


According to Stanford University’s Center for Research on Educational Outcomes (CREDO), in 2014-15 (the study's most recent data year) the average Texas charter student gains an extra 17-days’ worth of educational progress in both reading and math each year compared to their matched peers in traditional public schools.  Multiplying by 13 years spent in K-12, this adds up to roughly an extra 1.2 years’ worth of extra educational progress over the course of a K-12 education for the average student in a Texas charter school.  See CREDO, 2017, Charter School Performance in Texas.  While the charter value-add statewide is not as dramatic as it is in San Antonio, it is important to note that the last data year for the Texas study is two years prior to the San Antonio study's last data year.  A lot of high-performing charters have opened across the state in that time, though probably nowhere as fast as in San Antonio.  

Matthew Ladner of RedefinEd has looked at Texas 4th grade NAEP scores in 2018 and compared them to 8th grade NAEP scores 4 years later to get a rough idea how much progress the sector made in those 4 years.  The graph below provided by Matthew Ladner compares this progress for multiple states, including Texas, with the progress for Texas Charter School Students alone.  The difference is startling. 


Studies of charter competition's effect on students who remain in traditional public schools showing positive or neutral effects: Ridley & Terrier 2018 (Massachusetts), Cordes 2018 (New York City), Winters 2012 (New York City), Zimmer & Buddin 2009 (California), Winters 2009 (New York), Zimmer et al. 2009 (Texs, Chicago, Denver, Milwaukee, Philadelphia, San Diego, and Ohio), Booker et al., 2008 (Texas), Sass 2006 (Florida), Bifulco and Ladd 2006 (North Carolina), Bettinger 2005 (Michigan), Bohte 2004, (Texas), Holmes et al. 2003 (North Carolina), Hoxby 2002 (Michigan and Arizona), Greene and Forster 2002 (Milwaukee, San Antonio).