This paper provides a critical review of empirical and theoretical underpinnings of current research on declining rates of fertility in western countries, particularly Canada. Section 1 describes contributions of demographic analysis to the explanation of declining fertility in western industrialized countries and elaborates on the limits of pure demographic research with regard to factors that influence decisions of couples or individuals. Section 2 explores physiological and medical aspects of increasing infertility among the decreasing number of couples willing to have children. The section also notes the limited impact of this infertility on the explanation of the dramatic decline of fertility in western nations. Section 3 underscores the contribution of economic factors to the decline in fertility and exposes major shortcomings of one strictly economic logic. Section 4 illustrates contributions of a sociological approach to understanding fertility decline and finds that its central concepts remain excessively abstract and remote from essential processes through which human preferences and values are shaped and acted upon. Section 5 examines the contours and efficacy of pronatalist population policies implemented in some western nations. Section 6 summarizes major limitations of current research and offers recommendations for further investigation. Just over 100 references are cited. (RH)