Work- life Programs as Predictors of Job Satisfaction in Federal Government Employees

Work- life Programs as Predictors of Job Satisfaction in Federal Government Employees Danielle N. Atkins PhD Student University of Georgia Department of Public Administration and Policy Athens, GA 30602 dnatkins1@gmail.com

Introduction The U.S. workforce has undergone both demographic and sociological changes over the last several decades. In the past, work- life balance considerations in the workplace were not much of an issue because, in general, husbands were able to concentrate on work demands because wives were stay- at- home moms who managed family demands (Bruce and Reed 1994; Kanter 1997; Romzek, 1991; Saltzstein et al., 2001). This dynamic has changed significantly over the past several decades. Women have been entering the labor force at an increasing rate. In 1950, men comprised 40% more of the labor force than women, but in 2007, men accounted for only 9% more of the labor force than women (Families and Work Institute, 2008). During the recent recession, unemployment rates for men have been growing at a faster rate than for women (Families and Work Institute, 2008). In addition, mothers are making up an increasing share of the U.S. workforce. Almost half of mothers with children ages 18 years and under were working in 1975, and in 2007, 71% of mothers with children ages 18 years and under were in the labor force (Families and Work Institute, 2008). This change has been even more dramatic for the Federal government with the increasing proportion of women in Federal employment outpacing the increasing proportion of women employed in the private sector between 1976 and 1990 (Guy, 1993). In addition to demographic shifts in the U.S. workforce, sociological changes have been occurring as well. Since 1997, women ages 29 years and under have increasingly desired jobs with higher levels of responsibility. In fact, the data from the Families and Work Institute 2008 National Study of the Changing Workforce

indicate there is no longer any difference in the proportion of young women and men desiring jobs with greater responsibility (Families and Work Institute, 2008). Although young women s desire for greater work responsibility has been increasing, it is important to note that the results from the Families and Work Institute 2008 survey also indicate that 15% of young women who did not desire increasing work responsibility cited concerns with difficulties in managing personal and family responsibilities with increased job responsibility. Men s attitudes toward work- life balance have been changing over the past several decades as well. As of 2008, both sexes are less prone to believe that men should be responsible for earning income while women should manage family responsibilities than in 1977, and this change has been greater among men than women (Family and Work Institute, 2008). Fathers are spending a greater amount of time with their children and are taking on more responsibility with other family responsibilities such as cooking and cleaning today than in 1977 (Family and Work Institute, 2008). Although gender roles appear to be converging with respect to family responsibilities, satisfaction with work- life balance is diverging. The percentage of men reporting work- life conflict has increased from 35% in 1977 to 45% in 2008, whereas the percentage of women reporting work- life conflict increased only a small amount from 34% to 39% (Families and Work Institute, 2008). Demographic and sociological change has characterized the U.S. labor force over the past several decades. Many employers responded to these changes in the workforce by offering policies that help employees better manage work- life balance

such as child care programs, alternative work schedules, and telework, for example (Ezra and Deckman, 1996). Understanding the results of the introduction of these types of employee assistance programs into the workplace is important for successfully managing these types of policies and programs aimed at increasing satisfaction with work- life balance. This study analyzes a large survey of Federal government employees to examine the relationship between satisfaction with employee assistance programs and job satisfaction. I aim to address the following question: how important is satisfaction with work- life programs to overall job satisfaction? In particular, do these effects vary by sex? I hypothesize that satisfaction with work- life programs will be a significant predictor of overall job satisfaction. To test this hypothesis, I examine whether employee satisfaction with alternative work schedules, telework, child care, elder care, employee assistance programs, and employee health/wellness programs is a significant predictor of overall job satisfaction of Federal government employees. I expect that the impact of work- life programs will vary by sex, with satisfaction with work- life programs being a stronger predictor of job satisfaction for women than men. Data For this analysis, I use data from the 2010 Federal Employee Viewpoint Survey. This survey was administered to full- time, permanent, Federal employees of departments, large agencies, and some small/independent agencies. The organizations participating in this survey comprise approximately 97 percent of the Federal bureaucracy. The full sample for this analysis consists of 63,625 Federal

employees. I also disaggregate this sample based on sex. The female model has 28,005 employees, and the male model has 35,575 employees. In addition, the data have been weighted in order to provide a representative sample of the Federal workforce. The weighted means for the full sample, the female subsample, and the male subsample are presented in Table 1. Substantial differences in the means for the full sample and subpopulations are not evident. [Table 1 about here] Job Satisfaction and Work-Life Programs When organizations adopt these work- life programs, they are likely aiming to increase employee job satisfaction as one of their goals. Empirical research has linked job satisfaction to increases in organizational commitment, reductions in turnover, and employee advancement (Ezra and Deckman 1996; Families and Work Institute, 1998; Ford Foundation, 1997; Hochschild, 1997; Lewis, 1992). Although job satisfaction has been shown to be a predictor of these positive outcomes, job satisfaction has also been considered as a potential outcome in and of itself, and it will be used as an outcome measure in this analysis. Satisfaction with work- life balance has also been shown to have a positive effect on job satisfaction (Ostoff, 1993; Satlzstein et al., 2001). The extant literature focusing on the relationship between work- life programs and job satisfaction for Federal employees has been somewhat mixed. Ezra and Deckman (1996) analyze the relationship between onsite childcare and alternative work schedules on work- family satisfaction for three subsamples of Federal employees: mothers, fathers, and nonparents. In addition, they examine the link

between satisfaction with work- family balance and job satisfaction. Their findings indicate that work- family balance is a significant predictor of job satisfaction, and programs such as childcare and alternative work schedules help workers, especially mothers, maintain a satisfactory work- life balance (Ezra and Deckman, 1996). A study by the Ford Foundation finds that work- life programs can benefit not only employees by increasing responsiveness to employee needs but also leads to improvements in organizational performance (Ford Foundation, 1997). Saltzstein et al. (2001) examine the effect of work- family programs on both work- life satisfaction and job satisfaction among Federal employees and find that flexible schedules exert a small negative effect on job satisfaction, use of childcare programs has a positive effect on job satisfaction, and working from home also increases job satisfaction. I extend previous research in this area in two ways. First, I include a broader set of work- life programs than used in previous research. In addition, the most recent data utilized in the aforementioned analyses of Federal employees used the 1991 Survey of Federal Employees. The data used in this analysis are from the 2010 Federal Employee Viewpoint Survey. Dependent Variable: Job Satisfaction For this analysis, I use a five- point Likert scale measure of job satisfaction ranging from very dissatisfied, dissatisfied, neither satisfied nor dissatisfied, satisfied, and very satisfied.

Variables of Interest: Work Life Programs The independent variables of interest in this analysis are measures of employee satisfaction with multiple work- life programs including: elder care programs, child care programs, telework, employee assistance programs, wellness programs, and alternative work schedules. Each of these variables is measured using the same five- point Likert scale as the job satisfaction measure. Elder Care Elder care programs represent a growing concern for employers as the elderly population in America continues to grow. The number of elderly Americans is projected to grow to greater than 70 million by 2030, over double the current number (OPMb, 2011). The Office of Personnel Management (OPM) states that it is important that the Federal Government offer elder care programs, policies, and initiatives to assist employees who are currently, or who will be caregivers with family and work/life demands (OPMb, 2011). Given this goal, it is important to assess the relationship between satisfaction with elder care programs and job satisfaction. Childcare Programs Several Federal organizations offer child care assistance to employees such as child care at work or referrals to child care providers. In addition, low- income employees may utilize the Child Care Subsidy Program, which helps finance child care for low income employees with children under 13 years of age. Dependent Care Flexible Spending Accounts are also available to employees, which allow them to set aside a portion of their salary for dependent care expenses (OPMa, 2011).

Child care programs have been linked to job satisfaction in Federal employees in a couple of studies (Ezra and Deckman, 1996; Saltzstein et al., 2004). Telework Programs According to the OPM, increasing the utilization of telework in the Federal workforce is a high priority on President Obama s agenda. In addition, Congress passed the Telework Enhancement Act of 2010, which aims to help agencies improve the strategic use of telework in order to drive performance. Based on Employee Viewpoint Survey data, the OPM reports that teleworking is increasing in the Federal government (OPM, 2011). Since telework is taking such a prominent role in the work- life balance programs offered to Federal employees, its relationship to job satisfaction should be examined. Employee Assistance Programs Employee Assistance Programs (EAP) are available in all Federal agencies. These programs aim to assist employees with emotional distress, substance abuse, family problems and mental health problems by offering counseling or referrals to employees at no cost to the employee (OPMc, 2011). Wellness Programs Increasing usage of comprehensive worksite wellness programs in Federal agencies is a goal of HealthyPeople 2010. More specifically, HealthyPeople 2010 aims to increase the percent of worksites offering these programs to 75% and increase employee participation to 75% (OPMd, 2011) Alternative Work Schedules

Flexible work scheduling is thought to improve work- life balance by allowing employees to customize their schedules to account for personal responsibilities. In 1994, President Clinton urged all Federal agencies to implement programs aimed at increasing flexibility and family- friendly work policies for employees in and in 1996, directed Federal agencies to evaluate the progress of these programs and also implement programs aimed at increasing flexible hours to help employees balance work- family issues (OPMe, 2011). Control Variables Job satisfaction is a multi- faceted concept, and as such, an extensive set of control variables is included in this analysis to account for other correlates of job satisfaction. Yuan Ting (1997) uses the 1991 Survey of Federal Government Employees to identify determinants of job satisfaction among Federal government employees. The researcher argues that three types of characteristics drive job satisfaction of Federal employees: job, organizational, and individual. The findings indicate that job characteristics shown to increase job satisfaction include satisfaction with pay, opportunity for advancement, task clarity and significance. Organizational characteristics such as quality of relationships with co- workers and supervisors also predict job satisfaction in Federal employees. I base my inclusion of control variables for this analysis on this model of job satisfaction. I include a set of job characteristics to control for their effect on job satisfaction. These include satisfaction with information received from supervisors about what is happening in the organization, satisfaction with opportunities for advancement, satisfaction with training, and satisfaction with pay. I also include job

characteristics related to task clarity and significance including measures of level of clarity of work expectations, feeling that work is important, liking the job, involvement in decisions affecting work, and feeling of accomplishment resulting from work. In addition, I control for sufficiency of resources by estimating the model using measures of satisfaction with resources needed to perform the job, reasonableness of workload, and adequacy of physical conditions of the work environment. Organizational characteristics are also controlled for in this analysis. I include measures of relationships with supervisors including employee perceptions of senior manager and direct supervisor performance, leaders support of work- life programs, and direct supervisor s support of employee s need to manage work- life balance. I also control for the employee s relationship with coworkers by including a measure of how much the employee agrees that the people in their unit work together to accomplish work tasks. Both the job and organizational characteristics variables are coded as a five- point Likert scale as previously discussed and either indicate increasing levels of satisfaction or agreement. In addition to job and organizational characteristics, I also control for individual characteristics of the employees including sex, age, minority status, supervisor status, job location (headquarters or field), pay category, and tenure in Federal government. Analysis and Findings Although the ordinal nature of the job satisfaction dependent variable violates some key assumptions of Ordinary Least Squares (OLS) regression, I analyze the

data using both OLS and ordered probit specifications. Because the results from the ordered probit are not substantively different from the OLS results, and interpretation of OLS is more straightforward, the OLS results will be presented and discussed in this paper. The results for each of the specifications are presented in Table 2. [Table 2 about here] The results for the full sample indicate that increasing satisfaction with telework programs significantly increases employee job satisfaction. Satisfaction with EAP and job satisfaction are significantly and negatively related. Satisfaction with elder care programs, child care programs, wellness programs, and alternative work schedules do not significantly predict job satisfaction for the full sample of employees. Consistent with previous research, job characteristics significantly predict job satisfaction. The only job characteristic variable that does not significantly predict increased job satisfaction is the employee s agreement that there are clear expectations for what is required of them on the job. Increasing satisfaction with opportunities for promotion, training, and pay all significantly increase job satisfaction. Increasing beliefs that employees work is important, that their work gives them a sense of accomplishment, that they get to participate in decisions that affect their work and liking the work they do all significantly increase job satisfaction among Federal employees. Resources and physical conditions are not significant predictors of job satisfaction, but reasonable workload is positively and significantly related to job satisfaction. Organizational characteristics matter as well. Perceptions of the supervisor s performance and the supervisor s support for

the employee s need to balance work and other life issues significantly improve employee job satisfaction. Older employees are more satisfied with their jobs, and supervisors/executives are less satisfied with their jobs. Like the full sample, telework significantly increases employee job satisfaction for women and EAP significantly decreases job satisfaction for women. As hypothesized, increasing satisfaction with child care programs is significantly and positively related to job satisfaction for women, which is not the case for the entire sample. Unlike the entire sample, opportunities for advancement, the feeling that their work is important, and reasonable workload are not significant predictors of job satisfaction for women. In addition, perception of direct supervisor performance does not significantly predict job satisfaction for women. Like the full sample older women are more satisfied with their jobs and female supervisors are less satisfied with their jobs, but the significance on this last finding decreases dramatically for the female sample. The only work- life program that is significantly related to men s job satisfaction is child care, and the relationship is negative. At first glance, the finding that increasing satisfaction with child care programs is associated with a decrease in job satisfaction for men seems unexpected. One potential explanation for this finding may be related to the converging gender roles in the home and diverging levels of work- family conflict found in the Families and Work Institute 2008 National Study of the Changing Workforce. It may that the negative effect on job satisfaction associated with increasing satisfaction with child care programs for these male employees is capturing this increasing work- family conflict experienced by men.

Men responding to the question regarding satisfaction with child care programs who do not have children are likely to choose No Basis to Judge as their response. Men responding to this question likely have children. Based on the findings of the Family and Work Institute Study, fathers today are experiencing greater work- life conflict which may explain the decrease in job satisfaction for this particular group of male respondents. Consistent with the results from the full sample, job and organizational characteristics are important predictors of job satisfaction for the male subsample. Some notable differences include that clear expectations for work are only significantly related to job satisfaction for the male sample, cooperating with coworkers to get the job done is more significantly related to job satisfaction for men than the entire sample, and supervisor s support for need to balance work- life issues is still a positive predictor of job satisfaction for men but the significance level decreases relative to the full sample. Conclusion Overall, the findings from these models indicate that telework is a significant predictor of job satisfaction for Federal employees. In addition, female employees job satisfaction is significantly improved as their satisfaction with child care programs increases. EAP are negatively related to job satisfaction. The explanation for this finding is unclear. Men who are more satisfied with child care programs are less satisfied with their jobs; however, this may be an artifact of the increasing levels of work- family conflict experienced by men (Family and Work Institute, 2008). Consistent with previous research, job and organization characteristics are significant predictors of job satisfaction.

Although telework, child care programs, and EAP were significantly related to job satisfaction, satisfaction with elder care, health and wellness programs, and alternative work schedules were not significantly related to job satisfaction in this analysis. The explanation for this lack of findings is limited by the available data. It may be that these programs are less widely utilized; however, the Employee Viewpoint Survey does not collect data on the frequency of the utilization of these work- life programs. If one of the goals of implementing these types of programs in Federal government agencies is to increase job satisfaction, these results suggest that telework is successfully increasing job satisfaction for employees and child care is for female employees. However, EAP programs are associated with decreased job satisfaction and the remaining programs are not significantly related to job satisfaction. It may be that these relationships are not significantly related to job satisfaction because these programs are more instrumental in increasing work- life balance satisfaction than job satisfaction, which was not measured in this dataset. Future research in this area should aim to assess the relationship between work- life programs and outputs such as job satisfaction, organizational and individual performance, and work- life balance satisfaction. A richer dataset including utilization rates of work- life programs and a greater array of individual attributes such as data on family characteristics would be useful in evaluating the effects of work- life programs. Each of these programs is considered a priority by the OPM, and as such, the impacts of these programs should be assessed.

Works Cited Bruce, Willa, and Christine Reed. 1994. Preparing Supervisors for the Future Work Force: The Dual- Income Couple and the Work- Family Dichotomy. Public Administration Review 54(1): 36 43. Ezra, Marni, and Melissa Deckman. 1996. Balancing Work and Family Responsibilities: Flextime and Child Care in the Federal Government. Public Administration Review 56(2): 174 9. Families and Work Institute. 1998. The 1997 National Study of the Changing Workforce, executive summary. New York: Families and Work Institute. Families and Work Institute. 2008. The 2008 National Study of the Changing Workforce. New York: Families and Work Institute. Ford Foundation. 1997. Relinking Life and Work: Toward a Better Future, executive summary. New York: Ford Foundation. Guy, Mary Ellen, 1993. Workplace Productivity and Gender Issues. Public Administration Review 53: 279-82. Hochschild, Arlie.1997. The Time Bind: When Work Becomes Home and Home Becomes Work. New York: Henry Holt and Company. Hudson Institute. 1990. Workforce 2000 Work and Workers for the 21st Century. Washington, DC: U.S. Department of Labor. Kanter, Rosabeth Moss. 1977. Work and Family in the United States: A Critical Review and Agenda for Research and Policy. New York: Sage Publications. Lewis, Gregory. 1992. Men and Women toward the Top: Back- grounds, Careers, and Potential of Federal Middle Managers. Public Personnel Management 21(4): 473 91. Ostroff, Cheri. 1993. The Relationship between Satisfaction, Attitudes, and Performance: An Organizational- Level Analysis. Journal of Applied Psychology 77(6): 963 74. Romzek, Barbara S., 1991. Balancing Work and Nonwork Obligations. In Carolyn Ban and Norma M. Riccucci, eds., Public Personnel Management. New York: Longman Publishing. Saltzstein et al. 2001. Work Family Balance and Job Satisfaction: The Impact of Family- Friendly Policies on Attitudes of Federal Government Employees. Public Administration Review 61(4): 452-67. Ting, Yuan. 1997. Determinants of Job Satisfaction of Federal Government

Employees. Public Personnel Management 26(3): 313-34. U.S. Office of Personnel Management (OPM)a. Child Care. Work/Life. May 12, 2011, from http://www.opm.gov/employment_and_benefits/worklife /FamilyCareIssues/ChildCare/index.asp>. - - - - - - - - - - - - - - - - - - - - - - - - b. The Handbook of Elder Care Resources for the Federal Workplace. Work/Life. May 12, 2011, from http://www.opm.gov/ employment_and_benefits/worklife/officialdocuments/handbooksguides/eldercare resources/elder02.asp. - - - - - - - - - - - - - - - - - - - - - - - - - c. Employee Assistance Programs. Work/Life. May 12, 2011, from http://www.opm.gov/employment_and_benefits/worklife/healthwellness/eap/. - - - - - - - - - - - - - - - - - - - - - - - - - d. Federal Worksite Wellness Resources. Work/Life. May 12, 2011, from http://www.opm.gov/employment_and_benefits /WorkLife/HealthWellness/wellnessresources/worksitewellnessprogram.asphttp:/ /www.opm.gov/employment_and_benefits/worklife/healthwellness/eap/. - - - - - - - - - - - - - - - - - - - - - - - - - e. Handbook on Alternative Work Schedules. U.S. Office of Personnel Management. May 12, 2011, from http://www.opm.gov/ oca/aws/index.asphttp://www.opm.gov/employment_and_benefits/worklife /healthwellness/eap/. - - - - - - - - - - - - - - - - - - - - - - - - -. 2011. Status of Telework in the Federal Government: Report to the Congress. Washington, DC, OPM.

Means for Weighted Sample Full Female Male Min Max Job Satisfaction 3.91 3.89 3.93 1 5 Satisfaction with Elder Care Programs 3.09 3.08 3.09 1 5 Satisfaction with Child Care Programs 3.10 3.07 3.12 1 5 Satisfaction with Telework 3.15 3.16 3.14 1 5 Satisfaction with Employee Assistance Program 3.43 3.48 3.40 1 5 Satisfaction with Health/Wellness Programs 3.42 3.43 3.41 1 5 Satisfaction with Alternative Work Schedules 3.53 3.53 3.54 1 5 Satisfaction with opportunity to get a better job in organization 3.27 3.18 3.34 1 5 Satisfaction with the training received for present job 3.55 3.49 3.59 1 5 Satisfaction with organization 3.73 3.73 3.73 1 5 Satisfaction with pay 3.67 3.65 3.68 1 5 The work I do is important 4.40 4.42 4.39 1 5 Likes kind of work 4.26 4.25 4.27 1 5 Work gives feeling of personal accomplishment 3.97 3.98 3.96 1 5 Clear expectations 4.09 4.10 4.08 1 5 My workload is reasonable 3.45 3.40 3.48 1 5 Sufficient resources to get job done 3.28 3.29 3.28 1 5 Physical conditions allow employees to perform their jobs well 3.73 3.60 3.82 1 5 The people I work with cooperate to get the job done 3.88 3.83 3.92 1 5 Satisfaction with involvement in decisions that affect work 3.58 3.55 3.59 1 5 Senior leaders demonstrate support for Work/Life programs 3.55 3.52 3.57 1 5 Supervisor supports need to balance work and other life issues 3.97 3.93 3.99 1 5 Perception of upper management performance 3.62 3.60 3.63 1 5 Perception of direct supervisor performance 3.98 3.92 4.01 1 5 Minority 0.38 0.44 0.35 0 1 Female 0.41 1.00 0.00 0 1 Age Group 3.33 3.28 3.36 1 5 Supervisor 0.21 0.16 0.23 0 1 Headquarters 0.36 0.41 0.32 0 1 Pay Category/Grade 2.34 2.39 2.31 1 4 Tenure in Federal Government 5.07 5.15 5.02 1 7 Observations 63625 28005 35620

Table 2 - OLS Results Dependent Variable: Job Satisfaction Full Female Male Satisfaction with Elder Care Programs -0.009 (0.023) -0.015 (0.035) 0.006 (0.022) Satisfaction with Child Care Programs 0.010 (0.019) 0.063** (0.028) -0.042** (0.020) Satisfaction with Telework 0.023** (0.010) 0.035** (0.016) 0.008 (0.008) Satisfaction with Employee Assistance Program -0.028** (0.014) -0.045** (0.020) -0.008 (0.012) Satisfaction with Health/Wellness Programs 0.001 (0.009) -0.010 (0.015) 0.006 (0.010) Satisfaction with Alternative Work Schedules -0.004 (0.009) -0.020 (0.016) 0.011 (0.008) Satisfaction with opportunity to get a better job in organization 0.041*** (0.012) 0.013 (0.018) 0.063*** (0.012) Satisfaction with the training received for present job 0.100*** (0.014) 0.131*** (0.024) 0.077*** (0.011) Satisfaction with organization 0.374*** (0.018) 0.360*** (0.029) 0.380*** (0.016) Satisfaction with pay 0.063*** (0.012) 0.075*** (0.019) 0.056*** (0.012) The work I do is important 0.035*** (0.013) 0.029 (0.022) 0.036*** (0.013) Likes kind of work 0.163*** (0.017) 0.184*** (0.030) 0.148*** (0.015) Work gives feeling of personal accomplishment 0.089*** (0.020) 0.092*** (0.035) 0.089*** (0.016) Clear expectations 0.013 (0.013) -0.018 (0.021) 0.031** (0.013) My workload is reasonable 0.022** (0.010) 0.015 (0.018) 0.028*** (0.009) Sufficient resources to get job done -0.007 (0.009) 0.010 (0.015) -0.021** (0.009) Physical conditions allow employees to perform their jobs well -0.005 (0.009) -0.020 (0.013) 0.006 (0.009) The people I work with cooperate to get the job done 0.022* (0.013) 0.014 (0.021) 0.033*** (0.011) Satisfaction with involvement in decisions that affect work 0.130*** (0.017) 0.152*** (0.028) 0.114*** (0.015) Senior leaders demonstrate support for Work/Life programs -0.051*** (0.015) -0.059** (0.026) -0.044*** (0.014) Supervisor supports need to balance work and other life issues 0.044*** (0.017) 0.058** (0.026) 0.027* (0.014) Perception of upper management performance 0.006 (0.014) 0.021 (0.024) -0.004 (0.012) Perception of direct supervisor performance 0.051*** (0.014) 0.031 (0.022) 0.069*** (0.013) Minority -0.020 (0.017) -0.017 (0.028) -0.020 (0.018) Female 0.005 (0.018) Age Group 0.038*** (0.010) 0.047*** (0.014) 0.031** (0.012) Supervisor -0.041*** (0.014) -0.038* (0.023) -0.041*** (0.015) Headquarters -0.023 (0.017) 0.001 (0.027) -0.040** (0.017) Pay Category/Grade -0.014 (0.008) -0.002 (0.017) -0.021*** (0.008) Tenure in Federal Government 0.000 (0.005) 0.005 (0.009) -0.003 (0.006) Constant -0.299*** (0.074) -0.412*** (0.143) -0.211*** (0.053) Observations 63625 28005 35620 R-squared 0.712 0.704 0.724 Standard errors in parentheses * p<0.10 ** p<0.05 *** p<0.01