One of the most dramatic changes in the life of the elderly in the United States in the twentieth century is the rise in the proportion of elderly widows living alone. This paper examines this transformation by comparing the determinants of elderly widows’ living alone at four points in time, in 1910, 1940, 1960, and 1990. Logistic regression models of the probability of living alone are estimated. The results of these models are used to calculate the expected proportion of elderly widows living alone in various hypothetical scenarios of social change. This analysis suggests that no single factor is responsible for the rise in living alone among the elderly. Value changes, as represented by a variable for time, are shown to have strong and direct effects on the increased probability of living alone in old age in the late twentieth century, independent of the effect of rising income levels. These results are discussed in light of previous research on living arrangements of the elderly, which articulates demographic, economic, and cultural explanations for change.