Investing in mutual funds: the determinants of implied and actual net cash flows

Estimating the fund investors' demand plays an important role in the mutual fund management. In this line, mutual fund demand can be measured as the total net cash flows experienced by the fund during a period. Due to a lack of the data for inflows and outflows in some countries and databases, many authors estimate the net cash flows using fund size and return information. This rough measure, although being a good approximation, implicitly assumes an error in its calculation. For a sample of 2985 US open-end funds, we find evidence that estimating this implied fund flows, the error generated is higher for smaller funds, funds with higher returns, and for those experiencing higher levels of inflows or outflows. This lack of precision leads to a distortion in the estimation of the effect of some determinants on the mutual fund demand, especially when longer periods are considered when constructing the net cash flows.