Three broad categories of transformative changes have been recommended in The Economics of Biodiversity: The Dasgupta Review (henceforth Review): (i) The need to address the imbalance between our demands on Nature and its supply. (ii) The need to change our measures of economic success. (iii) The need for institutional change. However, what the private citizen would like to find in the Review differs from what someone in a government department or an international agency or a private company seeks. These notes have been prompted by the many virtual meetings I have had since the Review’s launch and they further explore aspects of the Review’s recommendations.

Based on data from the International Social Survey Program (ISSP), this study examines the extent to which cognitive dissonance regarding egalitarian attitudes toward the gender division of labour are associated with fertility rates in sixteen societies, representing Anglo American, Northern European, Western European and East Asian regimes. The findings show that although levels of support for gender equality in the realms of the family and the market are positively associated with fertility rates, an even stronger relationship to fertility emerges when weighing the differences between the levels of support for gender equality in each realm. The findings lend some corroboration to McDonald’s hypothesis, which suggests that declining fertility rates are influenced by contradictory expectations between gender equality for women in the home and market.

The incidence of dizygotic (Dz) twinning can be used as an index of natural human fertility. A retrospective study was done at The Royal Women's Hospital, Australia, to see whether the dizygotic to monozygotic (Mz) twinning ratio from one hospital can accurately reflect the national incidence of Dz twinning. The yearly twinning incidence from 1947–1997 was expressed as a Dz:Mz ratio, standardised for maternal age and plotted against previously published national statistics. The proportion of mothers born in Asia (of both singleton and multiples) between 1983–1997 was analysed to see whether different racial mixes might influence twinning trends. There were 5275 twins born of known sex and maternal age between 1947–1997. The agestandardised Dz:Mz ratio increased non-significantly from 1.39 in 1947 to 2.29 in 1953 (P = 0.08), underwent a significant decline to 0.73 in 1977, then remained stable until 1997 (P > 0.05). The same trends were also apparent when the data was pooled into 2-year groups with the increase from 1947/48–1953/54 becoming highly significant (P < 0.009). These trends observed in the hospital-based data were in close agreement with those found in the national statistics, with the exception of a rise in 1977–1982 only reflected in the Australia-wide data. In 1993, 2.6% of mothers were born in Asian countries; by 1997, this had risen to 10.6%. We found that the Dz:Mz ratio from one hospital closely reflects national twinning trends. Prospective studies must account for race, and would need around 200–300 twin pairs per year to minimise fluctuations of the ratio. Twin Research (2000) 3, 12–16.