Forecasting Using Long-Order Autoregressive Processes: An Example Using Housing Starts

A long autoregressive (AR) modeling procedure for monthly U.S. housing starts data is considered. Neither differencing to remove the trend, nor differencing to remove the seasonal component is required in this method. The model is fitted by a Householder transformation-Akaike AIC criterion algorithm. Forecast performance is compared to that obtained by the Box-Jenkins ARIMA method. The prediction error variance of the long AR model method tends to be smaller than the prediction error variance of the Box-Jenkins model method. The long AR method is well suited for housing market time-series which are characterized by both strong seasonal and slowly changing trend components.     

Abstracts

Quality & Quantity -     

Evolutionary diffusion: internal and external methods used to acquire encompassing,complementary, and incremental technological changes in the lithotripsy industry

This study links theories concerning methods that firms use to acquire technology with theories concerning types of technological change. We place particular emphasis on interorganizational relationships. We predict that firms will often acquire know-how needed for encompassing technological change through equity-based arrangements with other organizations, complementary technological changes through nonequity interorganizational arrangements, and incremental changes through internal R&D. Our theory draws on perspectives that emphasize the need to develop new competencies within a business organization and to protect the value of existing competencies. Our empirical analysis examines methods of technology acquisition that firms have used in the commercialization of medical lithotripters, which are devices that fragment stones in the kidney and gall bladder. The analysis contributes to a better understanding of how technology acquisition methods vary with the manner in which technological change relates to a firm's existing capabilities. The study also helps develop our understanding of the evolutionary processes by which capabilities diffuse through an industry. © 1998 John Wiley & Sons, Ltd.