Humans exhibit demographic buffering against variability and persistence in inflation environments

Inflation affects human fertility and survival; persistent inflation can translate into fluctuations in annual population growth rate. Existing studies have yet to systematically examine inflations impact on long-term growth rates across populations. Here, we examine whether high inflation variance and autocorrelation amplify long-term growth rates sensitivity to inflation, across 32 countries over 1971-2024. Additionally, we examine the effect of increasing inflation variance and autocorrelation on humans capacity for demographic buffering, i.e., reducing the temporal variance in vital rates most sensitive to growth. First, we construct inflation-dependent matrix population models using a hierarchical Bayesian framework. We then calculate the stochastic sensitivity and elasticity of population growth rate to inflation to quantify demographic buffering across a variance-autocorrelation parameter space. We find that the stochastic sensitivities of the growth rate increase with inflations variance and autocorrelation. However, we do not find support for the expected adverse effects of inflation variance and autocorrelation on humans capacity to buffer against inflation. Our framework provides a valuable tool for examining the impact of resource uncertainty on life history strategies in stochastic environments. We discuss how our framework can be extended to study the resource-dependent population dynamics within variable environments and across the tree of life.