We examine whether there has been a decline in the returns from Australian public investment in research on broadacre agriculture. Complementing a forthcoming paper by Mullen, we use alternative specifications for the regression equation, which employs the log of total factor productivity (TFP) as the dependent variable. The rate of return is computed on an annual basis rather than by using multi-year averages. In contrast to Mullen’s earlier preliminary analysis, we have now found some evidence of a decline in the rate of return on public R&D investment, lending some support to recently voiced concerns on this matter.