T HE basic purpose of this paper is to show that an improved understanding of longswing mechanisms in economic-demographic interactions may be attained with cross-spectral analysis even though spectral analysis has, to date, cast only doubt on the existence of such long swings. The superiority of crossspectral analysis to simple estimation of power spectra stems from its emphasis upon examining relationships among economic and other variables (Granger, 1966). For exploration of the long-swing hypothesis, spectral analysis suffers from a further disadvantage its results are sensitive to the form of the data analyzed (levels, rates of growth, or deviations from trend), while cross-spectral analysis is not (see section II). Application of both spectral and cross-spectral analysis to economic and demographic data in Sweden, the United Kingdom, and the United States indicates (1) results of spectral analysis are generally similar across the three countries and negative with respect to the long swing hypothesis; and (2) cross-spectral analysis shows quite different long-swing mechanisms at work while giving some positive confirmation to the Easterlin model of long swings for the United States.

N this paper, we first re-estimate the structural equations of the Puerto Rican Model (Dutta and Su, 1969) by seven alternative methods of estimation, and obtain predictions on endogenous variables by using seven sets of alternative estimates. We have obtained three different types of predictions -pure ex-post, pure ex-ante and partial ex-ante. We then compare the predictive power of the various estimators in terms of several descriptive criteria. The specification of the model remains as before (Dutta and Su, 1969). The model consists of 36 jointly determined variables and 36 equations. Twenty-three of these equations are stochastic, and the rest are definitional. Of the 23 behavioral equations, equations (1) to (6) explain consumption expenditures on food, services, other nondurable goods, housing, automobiles, and other durable goods; equations (7) and (8) describe private investment expenditures and changes in inventory investment; equations (9) to (16) cover imports including food, nondurable goods, automobiles, other durable goods, capital goods, raw material, payments on service account, and payments on all other service account; equations (17) to (19) determine exports, namely traditional exports, nontraditional exports, and exports of services; equations (20) to (22) deal with the production sector and explain gross product of three sectors, namely: agriculture, manufacturing, and all other industries and finally equation (23) explains wage share. The relations (24) through (36) are definitional. II Estimation

PpT HE purpose of this paper is to test empirically two propositions which have been closely, although not exclusively, associated with Milton Friedman in recent years. The first is the hypothesis that changes in monetary or fiscal policy variables are frequently ineffective in stabilizing some target variable because they are poorly timed.1 The second hypothesis, which was presented by Friedman and Meiselman (1963), is that the money supply is a more important determinant of aggregate demand than autonomous expenditures.2 We test these hypotheses by considering the effects of changes in fiscal and monetary variables upon the movements in gross national product within the framework of a small, short-run econometric model of the United States economy. In our model both money supply and government expenditure are regarded as autonomous manipulative policy instruments. A special feature of the study is a quarter-by-quarter investigation of the effects of changes in each of the two policy variables upon the movement of GNP. The period of investigation dates from the end of the Korean War (1954-I) to the beginning of serious military involvement in Vietnam (1963-IV). The plan of the paper is as follows: In section II we specify and estimate the structural equations of the model. Section III is concerned with a dynamic analysis of the system. Here we derive our estimates of the dynamic multipliers and examine the system for stability. In section IV we utilize the preceding results to determine the relative importance of each of the two policy variables during the sample period. Simplified criteria are suggested and applied for evaluating the actual operation and relative effectiveness of the two types of policy. The final section contains a summary of the main results and some concluding remarks.

Yiannis P. Venieris, Frederick D. Sebold, Richard D. Harper, The Impact of Economic, Technological and Demographic Factors on Aggregate Births, The Review of Economics and Statistics, Vol. 55, No. 4 (Nov., 1973), pp. 493-497