As well as creating the term "portfolio worker" - an idea formed by his own divergent career and which was subsequently borne out by the growth of small, individually run firms - it was Handy who proposed the Shamrock organisation as a business model.
In the third leaf were those including the portfolio workers, as well as temporary workers and part-timers.
Yet individuals who fit this description may not be very common and the term portfolio worker is now used more widely to refer to self-employed workers who work for a number of organizations or clients in exchange for fees.
We anticipate that optimism will have a moderating influence on the relationship between work stressors and job strain for portfolio workers because their work is a form of self-employment that depends on the vagaries of clients and therefore requires an optimist's ability to focus on positive outcomes and overcome negative events.
However, we anticipated that portfolio workers would experience variations in job characteristics allied to changes in demands from their clients.
For example, the number of people with second jobs in the UK increased by 68% to 1.2 million between 1984 and 2001, and 8.5% of people with second jobs also reported having a third job (Simic & Sethi, 2002), Of course not all these people were portfolio workers because, for example, the figures included individuals who have stable part-time jobs with different organizations.
In relation to demands and control, portfolio workers commonly believe that their work offers high levels of variety and autonomy (Cohen & Mallon, 1999; O'Shea, 2002).
To stay in business, these smaller organizations will depend more and more on alliances, strategic relationships, and what author and London Business School Professor Charles Handy calls "portfolio workers." These portfolio workers will build careers around the projects they handle for a number of organizations, rather than stay in one corporation and climb the ladder.
"The rest will be organized in 'mercenary groups' - portfolio workers, specialists who come in for projects as needed.