RAND Corporation

About: RAND Corporation is a nonprofit organization based out in Santa Monica, California, United States. It is known for research contribution in the topics: Population & Health care. The organization has 9602 authors who have published 18570 publications receiving 744658 citations.

Patients Using Chiropractors in North America : Who Are They, and Why Are They in Chiropractic Care?

Abstract: Summary of background data and objectives Alternative health care was used by an estimated 42% of the U.S. population in 1997, and chiropractors accounted for 31% of the total estimated number of visits. Despite this high level of use, there is little empirical information about who uses chiropractic care or why. Methods The authors surveyed randomly sampled chiropractors (n = 131) at six study sites and systematically sampled chiropractic patients seeking care from participating chiropractors on 1 day (n = 1275). Surveys collected data about the patient's reason for seeking chiropractic care, health status, health attitude and beliefs, and satisfaction. In addition to descriptive statistics, the authors compared data between patients and chiropractors, and between patients and previously published data on health status from other populations, corrected for the clustering of patients within chiropractors. Results More than 70% of patients specified back and neck problems as their health problem for which they sought chiropractic care. Chiropractic patients had significantly worse health status on all SF-36 scales than an age- and gender-matched general population sample. Compared with medical back pain patients, chiropractic back pain patients had significantly worse mental health (6-8 point decrement). Roland-Morris scores for chiropractic back pain patients were similar to values reported for medical back pain patients. The health attitudes and beliefs of chiropractors and their patients were similar. Patients were very satisfied with their care. Conclusion These data support the theory that patients seek chiropractic care almost exclusively for musculoskeletal symptoms and that chiropractors and their patients share a similar belief system.

Panel Attrition from the Panel Study of Income Dynamics Household Income, Marital Status, and Mortality

Abstract: This analysis is concerned with the determinants of panel attrition from the Panel Study of Income Dynamics and with its consequences for estimation of dynamic behavioral models which exploit the panel or longitudinal information-household income dynamics, marriage formation and dissolution, and adult mortality risk. We develop and estimate joint models of attrition and one or more of these substantive processes, and allow for correlation across the equations through random effects. Although we find evidence of significant selectivity in attrition behavior, the biases that are introduced by ignoring selective attrition are very mild.

The Geography of International Investment

Abstract: Multinationals have become increasingly important to the world economy. Overseas production by U.S. affiliates is three times U.S. exports, for example. Who is investing where, for sales where? Much foreign direct investment is between high-income countries, but investment in some developing and transition regions, while still modest, grew rapidly in the 1990s. Adjusting for market size, much investment stays close to home; adjusting for distance, much heads toward the countries with the biggest markets. Foreign direct investment is more geographically concentrated than either exports or production. Thus U.S. affiliate production in Europe is 7 times U.S. exports to Europe; that ratio drops to 4 for all industrial countries and to 1.6 for developing countries. Multinational activity in high-income countries is overwhelmingly horizontal, involving production for sale to the host country market. In developing countries, a greater proportion of multinational activity is vertical, involving manufacturing at intermediate stages of production. Thus only 4 percent of U.S. affiliate production in the European Union is sold back to the United States, whereas for developing countries the figure is 18 percent, rising to 40 percent for Mexico. Similarly, less than 10 percent of Japan's affiliate production in the EU is sold back to Japan, compared with more than 20 percent in developing countries. In models of horizontal activity, the decision to go multinational is a tradeoff between the additional fixed costs involved in setting up a new plant and the savings in variable costs (transport costs and tariffs) on exports. In models of vertical activity, direct investment is motivated by differences in factor costs. Tariffs and transport costs both encourage vertical multinational activity (by magnifying differences in factor prices) and discourage it (by making trade between headquarters and an affiliate more expensive). The major outward investors carry out much horizontal investment in large markets. For U.S. investors, this means Europe, especially the United Kingdom; for Japan and Europe, it means the United States. Most EU investments, however, stay within the EU. The major outward investors carry out much of their vertical investment closer to home: the United States, in Mexico; the EU, in Central and Eastern Europe; Japan, in Asia. This paper - a product of Trade, Development Research Group - is part of a larger effort in the group to study the location of economic activity. Anthony J. Venables may be contacted at a.j.venables@lse.ac.uk.

The Allocation of Functions between Man and Machines in Automated Systems

Abstract: : The report postulates that men are good at doing that which machines are not good at doing and machines are good at doing that which men are not good at doing. Thus men and machines are not comparable, but complementary, and the term 'allocation of tasks to men and machine' becomes meaningless. Rather a task must be done by men and machines.

Strategies of cooperation in distributed problem solving

Abstract: Distributed Artificial Intelligence is concerned with problem solving in which groups solve tasks. In this paper we describe strategies of cooperation that groups require to solve shared tasks effectively. We discuss such strategies in the context of a specific group problem solving application: collision avoidance in air traffic control. Experimental findings with four distinct air-traffic control systems, each implementing a different cooperative strategy, are mentioned.