Projecting growth of metropolitan areas.

PIP: "This paper is about the determinants of growth of [U.S.] metropolitan areas (MSAs)." The authors review and evaluate the relevant literature.^ieng

Do metropolitan areas mean anything? A research note.

"In this brief study, I ask the most elementary question about the coherence of [U.S.] central cities and suburbs: are their population changes correlated in any simple way?...Specifically, I ask the following question: suppose one knows the national population growth rate, whether an SMSA component is the central city (cities) or suburbs, and the region in which the SMSA is located, then would the ability to explain the component's population growth rate be improved by knowing which SMSA the component is in?... The conclusion is that there appears to be an SMSA effect on population growth."

The determinants of county growth.

PIP: The determinants of population and employment growth were explored from a broader interregional (as opposed to intraregional) perspective. Data for the 1970s, at the county level of disaggregation, were used to analyze the effects of economic, demographic, and climatic variables on population and employment growth in a simultaneous equation framework. The use of data from the more than 3000 US counties provides a considerably larger testing ground than those used in previous research. The point of departure was a conventional, general equilibrium model in which both households and producers are geographically mobile. The study's dependent variables refer to population, total, and manufacturing employment densities. Family income had a powerful effect in stimulating both population and employment density. A 10% increase in family income led to a 7.9% increase in total and a 9.2% increase in manufacturing employment densities. High family income must stand for high demand, and thus, firms are drawn to an area. High family income also drew households to an area. A 10% increase in family income led to a 5.5% increase in population density. High family income must represent "good" neighborhoods for households. High family income was positively correlated with population and employment density, but in other recent studies either a negative and significant relationship or an insignificant relationship were reported. Local taxes consist of the receipts of county government and those of municipalities, townships, school districts, and special districts within the county. The elasticities reported in Table 4 suggest that a 10% increase in such taxes resulted in about a 0.072% reduction in county population density during the decade. The Industrial Revenue Bonds (IRBs) and the percent of the labor force that is unionized are 2 potential policy instruments at the state level. The study results suggest that IRBs have not stimulated either manufacturing or total employment, and the coefficients were statistically insignificant in the structural equations. The elasticities imply that a 10% increase in percent union reduces total employment by 0.42% and manufacturing employment by 0.18%. The effect on population was tiny. Further, while not intended, the interstate highway program may have been a significant redistributor of population and employment but has not caused immigration of people and jobs from central cities.^ieng

Dynamics of rural-urban migration in India: 1960-1981.

"This paper analyzes a multi-sectoral simulation model of the Indian economy designed to isolate the sources of Indian economic growth and urbanization since 1960. The model shares many common traits with other computable general equilibrium (CGE) simulation models, and its underlying framework is neoclassical. The model stresses spatial issues so that it can provide predictions on rural/urban labor demands, and hence on migration flows. The central issue we seek to evaluate is whether a neoclassical development paradigm can explain adequately the somewhat paradoxical patterns of urbanization and economic growth observed in India since 1960. Our conclusion is a qualified, affirmative response, based on the model's ability to replicate key macroeconomic variables."

Some ultrastructural effects of insulin, hydrocortisone, and prolactin on mammary gland explants.

The effects of insulin, hydrocortisone, and prolactin on the morphology of explants from midpregnant mouse mammary glands were studied. Insulin promotes the formation of daughter cells within the alveolar epithelium which are ultrastructurally indistinguishable from the parent cells. The addition of hydrocortisone to the medium containing insulin brings the daughter cells to a new, intermediate level of ultrastructural development by effecting an extensive increase of the rough endoplasmic reticulum (RER) throughout the cytoplasm and an increase in the lateral paranuclear Golgi apparatus. When prolactin is added to the insulin-hydrocortisone medium, the daughter cells complete their ultrastructural differentiation. There is a translocation of the RER, Golgi apparatus, and nucleus and the appearance of secretory protein granules within the cytoplasm. There is excellent correlation between the ultrastructural appearance of the alveoli and their capacity to synthesize casein.

Mammary alveolar epithelial cells: effect of hydrocortisone on ultrastructure.

Hydrocortisone is necessary for the formation of rough endoplasmic reticulum in mammary alveolar epithelial cells. This membrane system is required for the synthesis of the milk protein, casein, but it is not required for the synthesis of a nonmilk protein fraction.