Supporters of the autonomy of higher-level causation (or explanation) often appeal to proportionality, arguing that higher-level causes are more proportional than their lower-level realizers. Recently, measures based on information theory and causal modelling have been proposed that allow one to shed new light on proportionality and the related notion of specificity. In this article we apply ideas from this literature to the issue of higher versus lower-level causation (and explanation). Surprisingly, proportionality turns out to be irrelevant for the question of whether higher-level causes (or explanations) can be autonomous; specificity is a much more informative notion for this purpose. 1 Introduction 2 Proportionality, Specificity, and Their Relevance for Higher-Level Causation and Explanation 3 Specificity and Proportionality Quantified 4 On the Limits of Higher-Level Causation and Explanation 4.1 On proportionality as an empirical matter 4.2 On how common proportional higher-level causes are 4.3 On the autonomy of higher-level causes 4.4 On the autonomy of higher-level causal explanations 5 Conclusion Appendix