We performed an analysis of the existing models and verbal theoretical arguments to establish the conditions in which they predict that a viable economy can be made compatible with zero and negative growth. This included a comprehensive and critical review of the literature to compile and assess the models that examine the conditions in which an economic system is found to be viable postgrowth, and to categorise them in terms of their theoretical frameworks, the modellers stated intentions, and their outcomes. This culminated in the construction of an integrated model that identifies the conditions in which these combined analyses suggest an economic system that is both viable and in which the continual increase of inequality is prevented; correspondingly, it also defines those parameters within which a postgrowth economic system will not be viable, and the conditions in which a postgrowth inequality is predicted to increase. We published our theoretical findings in the Review of Political Economy, presenting a simple framework identifying three types of policies for equality in postgrowth economies. One proposes redistributing wealth so that declining growth does not lead to rising inequality. A second strategy relies on decreasing rates of savings, through more spending or higher taxes on wealth. The third strategy relies on decreasing rates of returns to wealth, either as a deliberate policy goal or as an incidental result of measures that provide a minimum standard of living for the worst off. Our framework yields two main findings. First, in the absence of complete wealth equality, any strategy to prevent greater income inequality must reduce the income of the wealthy. Second, shifting to industries with a lower elasticity of substitution from capital to labour may prevent rising inequality for low-growth economies. We list a wide variety of specific policies that are already applied to some extent in various countries and which, in conjunction, could help prevent rising income inequality in a future non-growing economy. We published our empirical findings in Ecological Economics. For that publication, we conducted analysis of unpayable debts in slow- and non-growing economies compiling literature on ten different historical cases drawn from across Eurasia, Oceania, and the Americas, their dates ranging from bronze age societies of the 3rd millennium BCE up to the 19th century CE when the period of modern economic growth was just beginning. We found four main solutions to the problem of unpayable debts in historical economies: cancelling debts, banning the charging of interest, banning the compounding of interest, and various other limits to the size or length of loans. In none of our cases was a condition of zero net saving imposed upon the population; the condition which renders positive rates of interest compatible with zero growth in recent theoretical models. Though no website has been developed for the project, an ebook, a podcast, and a video explainer were produced to communicate the results to the general public.
