Charities Invest in Volunteers in a Variety of Ways. Thus far, we have discussed investments in paid staff and in volunteer management practices. Hiring someone who has training in volunteer management also demonstrates a greater investment in volunteer management. To derive an overall assessment of investment in volunteer management, we combined these three items into a single measure, describe below. Investments and Benefits Vary Together. We expect that the charities that invest in volunteers will be those that say they derive greatest benefits from volunteers. A comparison of the investments measure and the benefits index bears out this expectation. A Pearson’s correlation coefficient of indicates a moderate positive relationship between investment in volunteer.