This dissertation examines business cycles in Sweden, and the patterns in and driving forces of short- and long-term movements in unemployment in a selection of high-income countries throughout the 20^th century. While this has been studied numerous times before, this dissertation starts from the point of view that there is no consensus in social science on how to understand these phenomena. This study consists of an introductory chapter and four related but self-contained papers. One contribution of this thesis is the use of temporal disaggregation methods to estimate more detailed time series on gross domestic product (GDP) and unemployment. New quarterly estimates of GDP are then used, with the help of the Bry-Boschan algorithm, to reconstruct the Swedish business cycle in the period 1913–2014. This identifies a number of new patterns not visible in the annual data. A second contribution is different analyses of the extent to which unemployment can be explained by macroeconomic indicators such as GDP growth, capital formation and productivity. Different methods, such as band spectrum regression and wavelet analysis, are used to capture longer-term effects. Numerous results are presented that indicate that macroeconomic performance, notably capital formation, can have medium- to long-term effects on unemployment. This is in line with theoretical models on equilibrium unemployment that take account of the possibility of persistence in the return to long-run equilibrium, or models that comprise more than one unemployment equilibria. While this is not unknown in previous research, it contradicts several highly influential versions of equilibrium unemployment models, as well as a great body of research on the subject. These contributions have several important implications for future research. Historical chronologies should take account of the possibility that data of higher or lower frequency may lead to important differences in results. Empirical and theoretical research on labor markets should continue to investigate more deeply the possibility that unanticipated short-term events can have long-term effects on labor market outcomes.