Summary 

Digital labor platforms have made it easier for employees to take on side-hustles—offering additional income, personal fulfillment, and flexibility. Yet a critical tension persists: Can activities that energize employees after hours secretly drain their daytime effectiveness? Our study, recently published in the Journal of Management Studies, explores this paradox. We reveal how thriving in side-hustles creates competing forces: While some employees return to day jobs with sharpened focus from evening projects, others battle intrusive thoughts about side work during office hours. The key difference lies not in the side-hustle itself, but in the invisible psychological boundaries workers actively maintain—or let crumble. By dissecting this duality, our study reshapes understanding of multi-job careers in the digital age. 

Why care? 

Multiple jobholding has emerged as a significant and enduring global workforce trend, with 5%-35% of workers in industrialized nations maintaining concurrent employment across organizations. In China, over half the young workforce engages in supplemental employment—a phenomenon that fundamentally challenges traditional management theories predicated on single-employer models. 

Current research remains constrained by binary perspectives: Side-hustles are characterized either as compensatory mechanisms for career dissatisfaction (providing financial diversification and psychological security) or as threats to productivity through resource depletion and identity fragmentation. This dichotomous framework fails to accommodate emerging evidence demonstrating that side-hustles simultaneously produce both beneficial and detrimental effects, creating a paradox where identical activities can either energize or exhaust workers. 

The critical knowledge gap lies in our inability to predict the conditions under which side-hustles enhance rather than impair primary job performance. In the absence of such understanding, organizations face a policy dilemma: Either restrict employee autonomy by prohibiting side-gigs or risk burnout through excessive flexibility. Our research resolves this impasse by identifying the crucial determinant: workers’ capacity for mental role compartmentalization—an increasingly vital skill in today’s portfolio career landscape. 

How did we study this? 

To capture the dynamic interplay between side-hustles and full-time work, we conducted two complementary studies: 

1. Daily Experience Tracking: 97 employees logged their side-hustle experiences and full-time work outcomes over 10 days, yielding 644 observations. 

2. Longitudinal Multi-Source Surveys: 247 employees and their colleagues reported performance metrics across multiple weeks. 

What did we find? 

Side-hustle thriving acts as a double-edged sword for full-time work performance. Specifically, it enhances performance by fostering psychological detachment and affective well-being in employees’ primary roles (resource gain), yet undermines it through attention residue and resource depletion tied to the side-hustle (resource loss). Crucially, employees who actively segment boundaries between their roles amplify these gains while reducing losses. 

In other words, side-hustles don’t uniformly help or harm your main job—their impact hinges on how you mentally navigate between roles. Strategic compartmentalization of work domains turns side-hustles into a net positive, unlocking energy for full-time work while minimizing distractions. 

Why do these findings matter, and for whom? 

These insights are valuable for: 

1. Organizations and managers: The rise of side-hustles demands a strategic reorientation: from perceiving them as risks to leveraging their potential for skill diversification and innovation. Providing structured guidance on boundary management and aligning side-hustles with full-time roles can enhance performance and foster human capital growth. Restrictive policies risk disengagement; supportive frameworks foster adaptability and human capital growth. 

2. Human resources (HR) professionals: HR teams are crucial in developing policies and support systems that balance flexibility with guardrails. This includes designing career planning, skill development programs, and job design initiatives to support employees at different thriving levels, ensuring side-hustles enhance rather than detract from full-time performance. 

3. Employees with side-hustles: Employees must actively manage conflicts between their full-time jobs and side-hustles. Implementing boundary segmentation and selecting compatible side-hustles can minimize negative impacts on full-time work while maximizing benefits. 

In short, the dual impact of side-hustles demands proactive strategies: Organizations must balance flexibility with guardrails, while employees need to master boundary management to turn side-hustles into a career asset. 

What are the key takeaways? 

1. Support employee side-hustles strategically: Organizations should provide guidance and support to help employees manage their side-hustles effectively. This includes advising on how to choose compatible side-hustles and how to manage work hours, resources, and boundaries to separate work commitments. Supporting employees in establishing side-hustle goals that meet personal needs can enhance human capital development.  

2. Promote boundary segmentation: Employees should improve boundary segmentation skills, especially if they struggle with it. Targeted training or mental reinforcement can help demarcate boundaries between full-time jobs and side-hustles, reducing disruption and improving performance. 

3. Encourage thriving through challenge and connection: Employees with multiple jobs should seek to increase challenges in their side-hustles and cultivate harmonious interpersonal networks to foster a positive psychological state. However, organizations must also focus on supporting employees with lower side-hustle thriving by improving their psychological well-being through career planning, skill development, and job design. 

4. Balance resource gain and loss: For employees with high side-hustle thriving, organizations need to guard against potential full-time job resource depletion. Striking a balance between supporting employee growth through side-hustles and maintaining full-time job performance is essential for both employee well-being and organizational effectiveness. 

5. Provide growth opportunities: Organizations should meet the growth needs of employees by offering learning and training opportunities. Additionally, developing internal side projects can serve as a way for employees to pursue skill and experience growth within the constraints of their full-time work hours.