Principal characteristics' effect on teacher retention: A systematic review

Teacher attrition and retention are among the major problems in schools worldwide. Particularly in the United States, there is a great demand for teachers in elementary and secondary schools because of teachers transferring to new schools or resigning from the teaching profession altogether. This systematic review focuses on research on the prevalent decline of teacher retention in American elementary and secondary schools. This review aims to communicate reasons for the decrease in teacher retention and consider the impacts of teacher decline on students' academic success. Three databases – Web of Science, Science Direct, and Pro Quest – were utilized to obtain evidence to substantiate the causes and effects of the wave of teacher resignations. The evidence was analyzed to determine reliability using the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) and Cochrane review guidelines. The synthesis analysis included fourteen studies. It was clear from the synthesis that support and clear communication from school principals are essential factors of teacher retention in U.S. elementary and secondary schools. Other notable elements that prevent teacher turnover include recognizing the efforts of teachers, enforcing discipline and compliance among the student population, and conducting fair teacher evaluations. To improve teacher retention rates in the United States, school principals must adopt characteristics contributing to teacher retention.


INTRODUCTION
Several academic publications have pointed to the causes and effects of teacher attrition and retention.These publications document how poor academic performances of students and the high turnover rates of teachers were caused by the inability to retain highperforming teachers (Ronfeldt et al., 2013;Ingersoll and May, 2012).Challenges have contributed to teacher shortages in recent years, according to media channels in England and the United States (Hazell, 2018;Garcia and Weiss, 2019).Research suggests that the shortage of teachers in elementary and secondary schools may continue to increase steadily (Sutcher et al., 2016;Foster, 2019;TES Global, 2019).Unreasonable studentto-teacher ratios within the classroom could prompt teachers to leave the profession before retirement due to an overwhelming and disproportionate number of responsibilities.
The United States has a 20% teacher attrition rate, while the United Kingdom has an estimated attrition rate of 50% (See et al., 2020).Three countries, including France, Germany, and the Netherlands, were estimated to have a low (5%) teacher attrition rate (Carlsson et al., 2019).In Israel, first-year teachers leave the profession at an average rate of 41% per year, although the percentage may reduce to 19% in the third year of employment (Israeli Central Bureau, 2019).
There is a correlation between a decrease in the number of teachers and the quality of education students receive.In the absence of certified teachers, schools employ substitutes or temporary teachers with little or no experience in the teaching profession (Ronfeldt et al., 2013).A lack of experience in the teaching field alone does not undermine the academic influence of substitute teachers.However, substitute teachers are not always accustomed to school norms and procedures since substitute teachers are not full-time employees.Furthermore, the education levels and competencies required of certified teachers are not mandatory for substitute teachers.This means a substitute teacher may not possess the knowledge needed to assist a student with understanding schoolwork.Thus, teachers who are not certified may not be capable of adding value to the education of students due to a lack of knowledge and skill sets.Yet, substitute teachers are often needed to fill the voids of certified teachers who decide to find work elsewhere or retire early.Schools with low teacher retention tend to have increased costs since additional funds are needed for teacher recruitment each time a teacher resigns (Ryan et al., 2017).
Adverse experiences of teachers who have been in the field for at least ten years may cause poor teacher retention among those teachers at elementary and secondary schools.On the other hand, teachers new to the field of education have not yet dealt with the many stressors with which veteran teachers have had to contend.Hence, teachers new to the field of education are at the forefront of teacher attrition and are likely not yet seeking to move on from their recently established careers.When there is a high attrition rate among new teachers, it is probably because the professional development in the first year of teaching is challenging (Tillman, 2005;Carmel and Badash, 2018).The motivation to teach among new educators seemingly dwindles when teachers encounter many challenges, like navigating the complex dynamics among students while communicating with parents, during their associations with their colleagues, and relating to the school principal and other leaders.Moreover, teachers new to the field of education tend to deal with anxiety because they are adjusting to the use of recently obtained theoretical knowledge (Liu and Johnson, 2006).Additional factorsschool culture, work complexity, salary, incentives, and administrative attitudes toward older teacherssignificantly influence a teacher's decision to stay (Gavish and Friedman, 2010;Schaefer et al., 2012).Buchanan (2010) argues that a high workload, insufficient teacher support, and the lack of guidance largely explain why teachers, especially new ones, leave their positions.
Low teacher retention rates will likely increase in elementary and secondary schools if the factors causing the low rates are not addressed.Remote schools and schools already experiencing low teacher retention rates will suffer greatly.This projection has led to the need to mitigate ways to reduce the problem of low teacher retention.The role of the school principal is critical to developing resolutions needed to improve teacher retention rates.School principals have a significant influence on the teachers they lead.That influence, if used correctly, can lead to changes within the school that will motivate teachers to stay.A study conducted by Boyd et al. (2010) reported effective school principal leadership as the only significant factor that predicts teacher retention.In this study, researchers observed and measured the influence of principal leadership on K-12 teachers in New York City.The researchers used the following measurement criteria: school discipline policies, support from school administration, teacher evaluation process, and decision-making that includes teacher input.In another study, Allensworth et al. (2009) investigated the effects of principal leadership on K-12 Chicago teachers.Researchers in this study found a high teacher retention rate in school settings where teachers interact with school principals as instructional leaders.Likewise, high teacher retention rates were seen in schools where teachers were included in decision-making processes and in schools where teachers trusted in the abilities of the principal to lead.Ladd (2011) analyzed a North Carolina statewide survey on teacher retention.The study revealed that teachers value the support of a principal, student discipline, high student learning outcomes and instruction, a principal they can trust, inclusiveness in decisionmaking, and fairness in the teacher evaluation process.These aspects impact teacher retention.The researcher found these principal leadership characteristics as the most significant predictors of teacher attrition and retention rates in middle and high schools.
The role of a principal in teacher retention, such as supervision, contributes to discipline, professional  (Semarco and Cho, 2018;Grissom and Bartanen, 2019;Thomas et al., 2020).A high propensity for teachers to leave is often associated with negative perceptions of school principals.Poor support from the principal accounts for almost half of the teachers quitting.This claim was demonstrated by Kraft et al. (2016), who revealed principals' positivity and effective leadership as significant predictors of teacher retention.Multiple studies from different national contexts have also claimed a strong relationship between the characteristics of principals and whether teachers remain at the school.
Undoubtedly, evidence drawn from research findings has shown that several characteristics of the school principal are strongly associated with teacher retention and its correlated outcomes.However, despite primary studies indicating these associations, few studies have comprehensively reviewed all principal characteristics affiliated with teacher retention.Therefore, this systematic review aims to evaluate primary studies to reveal factors that predict teacher retention.

METHOD
Guidelines for this review follow preferred reporting items for systematic review and meta-analysis (PRISMA) statement (Page et al., 2021).Using the PRISMA framework, articles were obtained using eligibility criteria.The research process is in stages: (1) protocol development, (2) development of eligibility criteria that guides the inclusion and exclusion of studies, (3) database search for relevant studies, (4) title, abstract, and full-text screening based on inclusion criteria, (5) assessment of the studies for quality using an appraisal checklist, ( 6) data extraction and synthesis, and (7) reporting the findings of the synthesis.

Protocol development
Protocol development is the first stage of the systematic review process, which identifies the research questions following a specified framework.This review used the population/problem, intervention, comparison, outcome, and settings (PICOS) framework to develop the research questions based on the objective and what is obtainable (Table 1).
Following the framework below, a PICOS question was formulated: What characteristics of principals predict teacher retention in elementary and secondary schools in the U.S.?

Eligibility criteria
The eligibility criteria identify criterium for including and excluding studies in this current systematic review to enhance the quality and reliability of the study.

Inclusion criteria
-Only primary or empirical studies are considered in this study, and no limitation to the publication years -The study must contain primary data, and the non-restriction to publication years is to produce a comprehensive understanding of this phenomenon and reduce publication bias -Studies that obtain data primarily from the principals and teachers of elementary or secondary schools -Studies that investigate the role of principals in teacher retention or attrition -Studies with a measurable outcome of teacher retention -Only English studies are selected to avoid the shortcoming of non-English peer-reviewed studies.
-Studies that consider teacher retention as the willingness of teachers to stay within their current school or profession -Studies within the context of the USA

Exclusion criteria
-Non-primary and non-empirical studies -Studies examining other interventions beyond the characteristics of principals -Studies not looking at teacher retention as an outcome -Non -English articles -Studies without a measurable outcome of teacher retention -Studies not within the context of elementary or secondary school -Studies not within the context of the USA

Search strategy
This study utilizes the query of three primary electronic databases -Web of Science (WOS), Science Direct, and ProQuest -to retrieve relevant articles.Inclusion criteria widened the scope of the article searches.The three databases were searched using simple and general search strings.The search strings used for the database searches were principal, teacher retention, and teacher attrition.

Article screening and selection
Following the database search, the retrieved studies were screened Was the data collected from a reliable source?QA5 Was the outcome measured reliably?
Source: Author based on the defined inclusion criteria using the PRISMA screening protocol.

Risk of bias assessment
The quality and the potential bias of information used in this systematic review were assessed.The assessment determined the quality and reliability of the findings presented in this study.
Establishing the validity of the results will lead to revamping educational policies and new procedures.The evidence was assessed using five (5) risk bias assessment questions as criteria developed by the author to support the objectives of this research.
One objective is to avoid presenting non-reliable information (Table 2).The first risk bias assessment question in the research design -Was the research design appropriately congruent with the proposed objective?-evolved from information available in the studies gathered for this review.The second question -Does the study describe the study subjects and setting?-refers to the location and environment of the school, as well as the demographical data of the principals and teachers.Thirdly, the sample size is evaluated for sufficiency -Was a large sample considered?
The fourth question investigates the reliability of the data -Was the data collected from a reliable source?Finally, the method in which the outcome was measured is examined -Was the outcome measured reliably?The criteria were rated on a 0-3 scale per checklist.The overall rating for the five questions was 15.A score of 12 or greater signified that the quality of evidence was high.Evidence was moderately high if the assessment score was between 8-11 and low if there was a score for quality below 8.

Data extraction
A synthesis form was designed to match the research objective.The synthesis was used to extract meaningful information from the included studies.The information included author details, publication year, research design, study settings, school settings, principal associated factors (intervention), and outcomes.

Article selection process
A search of three electronic databases returned a total of 558 references, which were exported in a CSV (commaseparated values) format to Microsoft Excel, where citations were managed.The sources were sorted and filtered to exclude 231 references that were duplicates.The remaining 327 citations were screened and evaluated.In this process, 299 non-eligible articles were excluded, mainly because they were not within the scope of the research on which this systematic review is based.
The full text of 27 eligible resources was reviewed to evaluate the data for each study -research objectives, methodologies, findings, and conclusions.Following the full-text screening, only 12 studies met the inclusion criteria for this review.However, 12 of the studies were excluded because the studies were not conducted within the context of the U.S., did not incorporate a nonprincipal associated intervention, and did not relay a clear outcome (Figure 1).

Quality assessment
The 14 eligible studies were assessed for quality using the five risks of bias assessment questions.The 14 studies were considered high quality, with each scoring an overall 13.The studies utilized designs appropriate for the proposed research objectives of this systematic review.The subject and setting in the 14 studies were clearly described.Of the 14 studies, 9 utilized a large sample size to examine the impact of school principals' characteristics on teachers' retention.
The studies by Boyd et al. (2010), Brown and Whynn (2009), Easley (2006Easley ( , 2008) ) and Youngs (2007) used small to medium samples.Outcomes documented in the 14 studies were reliably measured in clear terms.The summary of the assessment of each study is shown in Table 3.

Characteristics of included studies
In total, 14 primary studies were reviewed to determine how principal characteristics affect teacher retention rates in the U.S. The studies were published over nine years, spanning from 1998 to 2018.The years with the most publications eligible for this review were 2007 and 2018; each with three studies (Figure 2).The 14 studies were published in 11 journals.The American Educational Research Journal, Leadership and Policy in School Journal, and the Journal of Educational Administration each published two studies for a total of 6 analyzed for A retrospective survey approach enabled researchers to obtain a large sample size as they combined data from readily available national surveys.Study subjects were either teachers or principals, or both in some cases, of elementary, middle, or high schools.A different method of analysis was used in each study to explore the relationship between the independent variable (principal associated characteristics) and the dependent variable (teacher retention).The synthesis analysis revealed multiple principal characteristics that predict whether a teacher intends to stay at the school, leave for employment at another school or district, or completely abandon the teaching profession.About 23 principal characteristics were extracted from the studies.Of these 23 characteristics, eight were reported by two authors.The eight characteristics are principal support and encouragement, clear communication, teacher recognition for a job well-done, principal-enforced disciplinary policies, support for teachers, and fair performance evaluations.Other notable characteristics include adequate allocation of resources, protection from external pressure, principal professional commitments, growth, and learning (Table 4).
Each study reported that characteristics of elementary, middle, high, and special population school principals were shown to have positive effects on the intentions of the teacher to remain in their current teaching roles.Notably, Dahlkamp et al. (2017) was the only researcher who reported principal self-efficacy, which was shown as

S/N Principal Characteristics Reference
1 Support and encouragement Boyd et al., 2010;Brown and Whynn, 2009;Easley, 2006;Gersten et al., 2001;Hancock and Scherff, 2010;Player et al., 2017;Singh and Billingsley, 1998;Olsen and Huang, 2018;Urick, 2016;Wynn et al., 2007 2 Clear communication Player et al., 2017;Singh and Billingsley, 1998;Olsen and Huang, 2018;Urick, 2016;Wynn et al., 2007 3 Teacher recognition for a job well done Player et al., 2017;Singh and Billingsley, 1998;Olsen and Huang, 2018;Urick, 2016 4 Enforced disciplinary policy and support for teachers Boyd et al., 2010;Player et al., 2017;Olsen and Huang, 2018;Urick, 2016 5 Fair performance evaluation Boyd et al., 2010;Singh and Billingsley, 1998;Youngs, 2007 6 Adequate resources allocation Boyd et al., 2010;Wynn et al., 2007 7 Protection external pressure Boyd et al., 2010;Youngs, 2007 8 Principal professional commitment, learning, and growth Brown and Whynn, 2009;Grissom et  Source: Author having a minor impact on the decision of a teacher to stay at a school.Other characteristics -such as border district and bureaucratic dysfunction, inadequate resource provision, lack of relevant information, and limited decision-making power -were reported to affect whether a teacher decides to leave a school directly.The summary of the synthesis analysis is presented in Table 4.

DISCUSSION
The characteristics of U.S. school principals, predictors of U.S. teacher retention, have never been systematically reviewed.This review of studies provides an understanding of how principal characteristics/behaviors/ attitudes in schools project teacher retention.This review focuses on how school principals play a vital role in teacher management.Without considering other variables, the characteristics exhibited by the principals are important modifiers and predictors of the devotion of teachers to their present jobs and the teaching profession.
Principal support and encouragement had the most influence on teacher retention rates.Principals who support and encourage their teachers tend to receive teacher loyalty, which causes high teacher retention rates.
The effect of support and encouragement on teacher retention was confirmed in the synthesis analysis, with approximately 72% of the studies claiming principal support and encouragement as significant predictors of teacher retention (Boyd et al., 2010;Brown and Whynn, 2009;Easley, 2006, Gersten et al., 2001;Hancock and Scherff, 2010;Player et al., 2017;Singh and Billingsley, 1998;Olsen and Huang, 2018;Urick, 2016;Wynn et al., 2007).
Regardless of the school location (rural or urban) and the school type (elementary, middle, high, special), the characteristic of principal support remains a significant predictor of U.S. teacher retention and attrition.This finding is like the conclusions made in several other studies published in the context of other countries.A good example is the study conducted by Gomba (2015) in Zimbabwe.The study confirmed that the commitment and support of a principal for novice and experienced teachers are determining factors in the decision of a teacher to remain in the profession.The findings are unsurprising, as several scholars have indicated that principals are vital stakeholders in teacher retention issues (Boyd et al., 2010).
Teachers who experience professional and careerbased support from the school principal tend to remain in the school with no plans of leaving the profession.Principals who provide professional and career-based support encourage teachers by listening to concerns, offering viable resolutions, and granting professional development opportunities.These responses from school principals inspire and promote perseverance, determination, and a sense of belonging to an organization where leaders care for the employees.A multi-level LCA (life-cycle assessment) of 35,560 teachers from 7,310 public schools in the U.S. identified supportive principal attitudes as a reason teachers remained in the profession (Olsen and Huang, 2018).
Principals with supportive attitudes toward teachers will likely create an academic environment where teachers thrive and are understood.Player et al. (2017) argue that regardless of the school and teacher characteristics, principal leadership in support significantly influences teacher interest in the passion for educating youth.Additionally, support received to assist with instruction delivery is a fundamental need of teachers, and when this need is met, teachers are likely to feel they can function with ease.Principal support has the most significant impact on the teacher retention model compared to other factors.Job satisfaction is correlated with an incredible feeling of supportive leaders (Whynn et al., 2007).Furthermore, principal support is a protected characteristic that enhances teachers' job satisfaction and reduces the potential for teacher burnout and turnover (Olsen and Huang, 2018).
Clear communication is another principal characteristic revealed as a predictor of teacher retention.The findings of this systematic review show that when principals communicate the school vision, school operating procedures, and expectations, they positively affect teacher retention rates (Singh and Billingsley, 1998;Wynn et al., 2007;Urick, 2016;Player et al., 2017;Olsen and Huang, 2018).Player et al. (2017) emphasized that communicating school visions to staff and working together to achieve the vision builds team cohesion and increases teacher retention rates if embraced.Using national data regarding Pre-K-12 public school teachers, Olsen and Huang (2018) advised that communicating expectations, procedures, and school operations to teachers can promote teacher retention.Through clear communication, principals articulate clear objectives that enable teachers to stay mission-focused and engaged, reinforcing purpose.When overwhelmed with responsibilities, a sense of purpose and understanding of the school's mission can easily redirect teachers to their passions for education.
Recognizing teachers for a job well done is another characteristic consistently reported to increase teacher retention rates in the United States (Singh andBillingsley, 1998, Urick, 2016;Player et al., 2017;Olsen and Huang, 2018).A sense of appreciation makes teachers feel valued and validates their commitment of teachers to the profession.Teachers tend to resign from schools where they are not appreciated for their accomplishments and roles in educating youth.A teacher is inclined to remain at a school where they feel valued.Lambersky (2016) argued that by recognizing and appreciating teachers' abilities, commitments, and sacrifices, principals could influence the emotions of teachers and compel teachers to remain at a school.
Enforcing disciplinary action to control students' behavior and backing teachers in such actions are vital.Respecting the authority of teachers to make the best decisions for the development of students can build upon the trust teachers have in their principals (Boyd et al., 2010, Urick, 2016;Player et al., 2017, Olsen andHuang, 2018).Principals who evaluate teachers fairly are likely to have highly committed teachers, and the teachers are less likely to leave the school and teaching profession (Singh and Billingsley, 1998;Youngs, 2007;Boyd et al., 2010).A fair and honest evaluation of teacher performance enables principals to communicate the areas in which teachers excel and areas in which improvements are necessary.Evaluations foster trust and understanding between teachers and principals, and this trust enhances teacher satisfaction and gives a reason for teachers to stay at the school where they work.
In most cases, allocating adequate resources to facilitate teaching is a common stressor for teachers.When teachers have the tools to do their jobs, teacher interest is sustained in the profession (Wynn et al., 2007;Boyd et al., 2010).Gersten et al. (2001) stated that lack of resources and information are essential factors why teachers leave schools.Protecting teachers from external pressures makes teachers develop more confidence in principals, as teachers feel supported (Youngs, 2007;Boyd et al., 2010).Providing support is a way of affecting teachers' psychological and emotional stability, and ultimately behaviors.A Canadian study by Lambersky (2016) explains that teachers who experience harassment and threats tend to transfer to other schools or quit teaching.
The principal's professional commitment and growth characteristics also contribute to teacher retention.Brown and Whynn (2009) and Grissom et al. (2019) reported that principals with high professional commitment and dedication to learning and growth inspire teachers to stay committed.Committed principals encourage professional development and improve teachers (Young, 2007).
Respect for teachers is another principal characteristic.Giving teachers the necessary respect builds trust and camaraderie between teachers and principals, thus creating a harmonious environment (Easley, 2007).Communication and interaction become easy when there is respect and trust, as the teacher believes the principal is approachable and sensible.When principals are helpful and communicative, they can retain teachers (Singh and Billingsley, 1998).
Communication through counseling can go a long way and creates a community facet to the school environment for teachers.Principals who communicate regularly with their teachers will likely know when to reduce teacher responsibilities under stressful conditions to avoid low turnover and burnout, which can lead to attrition (Wynn et al., 2007).A principal who provides constant feedback is likelier to have a high retention rate because less focus is given to less critical issues and emphasis is placed on the right thing (Easley, 2007).Teacher autonomy is another important component of teacher retention issues.Allowing the influence and authority of teachers over their students while remaining in compliance with school practices and policies is critical to empowering teachers in their roles.When teachers are not entrusted to function fully in their roles, they may find another place of employment.A survey was conducted using 4,360 New York City teachers in one of the included studies.Analysis of the survey findings shows that school principals who include teachers in processes, such as selecting curriculum and resources, scheduling activities, and choosing professional development opportunities, satisfy teachers and their sense of autonomy, which affects their decisions to remain with the school.An analysis of 50,000 Chicago public school teachers by Allensworth et al. (2009) shows that teachers remain committed to schools where they have a voice in school decisions.Gersten et al. (2001) added that limited decision-making power could affect teacher retention.Creating border district and bureaucratic dysfunction by the principal is a negative characteristic that affects school retention (Easley, 2006).Dahlkamp et al. (2017) added that principal self-efficacy does not significantly affect teachers' retention rates.

Limitation and future research
The findings of this systematic review are limited to elementary and secondary schools within the United States, and thus, generalizations cannot be made.However, some of the conclusions of the studies used for this systematic review are like the findings of studies conducted outside of the U.S. Also, the results of the studies used in this review were not specific to either rural or urban schools.There is a need for more thorough research on factors that hinder and contribute to teacher retention in elementary and secondary schools.This systematic review identifies the need for more empirical research on this topic, as few or no studies have been published on these issues in the U.S. within the last four years.

Conclusion
This systematic review summarized the principal characteristics of teacher retention in U.S. elementary and secondary schools.The findings of this study have contributed to the education field and teachers' advocacy for retention.The results of this study suggest that principal characteristics, particularly the support for teachers and open, clear communication, have a considerable impact on teacher retention rates.Schools where principals fail to display support for teachers and where standards and expectations are not communicated effectively experience low retention rates.Recognizing teachers for a job well done is an essential characteristic of principals that must be considered to encourage teacher commitment and reduce attrition.Fair teacher evaluations and adequate resource allocation contribute to improved teacher retention rates.It is pertinent to understand that school principals who support teachers during student disciplinary actions enhance teachers' trust and respect for them.Teacher inclusion in school decision-making processes increases the school value system.Allowing the teacher to contribute will make them feel valued as an integral part of the school system.Inclusion enhances the likelihood of teachers staying at a school and continuing to work in the education profession.When principals of elementary and secondary schools are willing to use practical management skills to care about the teachers charged with educating youth, teachers want to remain committed.

Table 2 .
Risk of bias assessment questions.

Table 4 .
Principal associated characteristics predicting teachers' intention to stay or leave.