This synthesis chapter seeks to draw general lessons from the case studies presented in the book. It does not include a review or summary of each chapter. Instead, we revert to themes that emerged from earlier in the book. Specifically, we argue that appropriately assessing living standards is challenging, and focus on the different nature of the challenges for consumption poverty line estimation and multidimensional poverty measurement. The six case studies uniformly indicate that the process of drawing appropriate absolute poverty lines is not straightforward and cannot be done mechanically. This is so principally due to five key factors: heterogeneity, volatility, vulnerability, data, and theory. The first three factors are usefully grouped together. In all of the case countries considered, poor people are heterogeneous, frequently live in environments with strikingly high levels of volatility, and are, almost by definition, vulnerable to shocks.