Short-run Birth and Death of U.S. Manufacturing Firms: 2000 - 2005

Attracting manufacturing investment remains a viable regional development policy. Previous research in the location literature has informed policymakers which factors are most important for attracting new firm investment. Far less is known about the dynamics of firm death and the possible interaction with firm birth. A conceptual model of county-level investment in the U.S. manufacturing sector is developed from location theory and subsequent literature. Specifically, we test the relative importance of location factors influencing firm investment, and if these factors influence firm birth and death differently. Local factors include labor quality, availability, and cost, market conditions, agglomeration due to localization and urbanization economies, infrastructure, and fiscal policy. This study covers the time period 2000 to 2004 for U.S. counties in the lower 48 states. Firm data are from the U.S. Census Bureau’s Dynamic Firm Data Series, which links establishments across space and time. Regional adjustment models are used to show how ceteris paribus changes in location factors affect the birth and death rates in a county.location factors, manufacturing, creative destruction, Community/Rural/Urban Development, L60, R11, R12,

A TWO-STEP ESTIMATOR FOR A SPATIAL LAG MODEL OF COUNTS: THEORY, SMALL SAMPLE PERFORMANCE AND AN APPLICATION

Several spatial econometric approaches are available to model spatially correlated disturbances in count models, but there are at present no structurally consistent count models incorporating spatial lag autocorrelation. A two-step, limited information maximum likelihood estimator is proposed to fill this gap. The estimator is developed assuming a Poisson distribution, but can be extended to other count distributions. The small sample properties of the estimator are evaluated with Monte Carlo experiments. Simulation results suggest that the spatial lag count estimator achieves gains in terms of bias over the aspatial version as spatial lag autocorrelation and sample size increase. An empirical example deals with the location choice of single-unit start-up firms in the manufacturing industry in the US between 2000 and 2004. The empirical results suggest that in the dynamic process of firm formation, counties dominated by firms exhibiting (internal) increasing returns to scale are at a relative disadvantage even if localization economies are presentcount model, location choice, manufacturing, Poisson, spatial econometrics

Manufacturing Transition in Local Economies: A Regional Adjustment Model

This paper addresses changes in capital formation by testing the importance of location factors with respect to the rate of establishment births and deaths in U.S. manufacturing, 2000–2004. A theoretical concept called “localized creative destruction” is tested as a mechanism to explain the dynamics impacting the spatial distribution of manufacturing establishment birth and death rates. While no support of this process was found, results identify a convergence process occurring where counties with high initial birth/death rates have smaller changes in firm birth and death rates. The interpretation is that counties become more equally competitive in terms of firm formation dynamics in lieu of successful counties increasing their lead in the short run. This is potentially relevant to policymakers and economic development practitioners who are concerned with business retention and the impact of new manufacturing establishments on their existing base.location determinants, manufacturing, adjustment models, Community/Rural/Urban Development, L60, R11, R12,

Firm Birth and Death in U.S. Manufacturing: A Regional Adjustment Model

Attracting manufacturing investment is a frequently used rural development policy. Previous research in the location literature has informed policymakers which factors are most important for attracting new firm investment. Far less is known about the interaction of birth and death of establishments. A conceptual model of county-level investment in the U.S. manufacturing sector is developed from location theory and subsequent literature. Specifically, we test the relative importance of location factors influencing firm investment, and if these factors influence firm birth and death differently. Local factors include agglomeration due to localization, urbanization, and internal economies, market structure, labor quality, availability, and cost, market conditions, , infrastructure, and fiscal policy. This study covers the time period 2000 to 2004 for U.S. counties in the lower 48 states. Counts of establishments are from the U.S. Census Bureau’s Dynamic Firm Data Series, which links establishments across space and time. Negative binomial models containing spatially lagged endogenous variables are estimated in a regional adjustment framework to show how ceteris paribus changes in location factors affect the conditional number of establishment births and deaths in a county.location determinants, manufacturing, count models, Community/Rural/Urban Development, Research Methods/ Statistical Methods, L60, R11, R12,

Experimental verification of the multistage depressed collector design procedure for a high-perveance, helix-type, traveling-wave tube

The validity of a computational procedure for the design of multistage depressed collectors (MDC's) is demonstrated for a traveling wave tube (TWT) with a perveance of .00000123. The MDC is used with spent-beam refocusing to improve substantially the efficiency of the TWT. Reports on this subject have verified, under a variety of operating conditions, the MDC design procedure for TWT's with lower perveance. The design procedure is based on two computer programs that create a mathematical model of the electric and magnetic fields of the TWT refocuser MDC system and its electron beam. The two principal outputs of the analysis are a description of the radiofrequency (RF) performance of the TWT and the trajectories of representatives groups of charges from the input of the TWT to their points of interception on the MDC electrodes

Analytical prediction with multidimensional computer programs and experimental verification of the performance, at a variety of operating conditions, of two traveling wave tubes with depressed collectors

Experimental and analytical results are compared for two high performance, octave bandwidth TWT's that use depressed collectors (MDC's) to improve the efficiency. The computations were carried out with advanced, multidimensional computer programs that are described here in detail. These programs model the electron beam as a series of either disks or rings of charge and follow their multidimensional trajectories from the RF input of the ideal TWT, through the slow wave structure, through the magnetic refocusing system, to their points of impact in the depressed collector. Traveling wave tube performance, collector efficiency, and collector current distribution were computed and the results compared with measurements for a number of TWT-MDC systems. Power conservation and correct accounting of TWT and collector losses were observed. For the TWT's operating at saturation, very good agreement was obtained between the computed and measured collector efficiencies. For a TWT operating 3 and 6 dB below saturation, excellent agreement between computed and measured collector efficiencies was obtained in some cases but only fair agreement in others. However, deviations can largely be explained by small differences in the computed and actual spent beam energy distributions. The analytical tools used here appear to be sufficiently refined to design efficient collectors for this class of TWT. However, for maximum efficiency, some experimental optimization (e.g., collector voltages and aperture sizes) will most likely be required

Preliminary Canopy Removal Experiments in Algal Dominated Communities Low on the Shore and in the Shallow Subtidal on the Isle of Man

The algal dominated communities immediately above and below the low-water spring level on a moderately exposed Manx shore were investigated by canopy removal experiments. Fucus serratus, Laminaria digitata and L. hyperborea were removed. Competition was shown to be important in determining the zonation of L. digitata and the distribution along the wave exposure gradient of other species such as Alaria esculenta, Desmarestia aculeata and D. viridis, and L. saccharina. Many species of algal epiphytes were early colonizers of canopy removal areas suggesting that competition from canopy algae usually restricts them to an epiphytic habit. The results indicate that interactions between macrophytes are much more important than grazing in structuring these communities

Verification of computer-aided designs of traveling-wave tubes utilizing novel dynamic refocusers and graphite electrodes for the multistage depressed collector

A computational procedure for the design of TWT-refocuser-MDC systems was used to design a short dynamic refocusing system and highly efficient four-stage depressed collector for a 200-W, 8- to 18-GHz, TWT. The computations were carried out with advanced, multidimensional computer programs which model the electron beam as a series of disks of charge and follow their trajectories from the RF input of the TWT, through the slow-wave structure and refocusing section, to their points of impact in the depressed collector. Secondary emission losses in the MDC were treated semi-quantitatively by injecting a representative beam of secondary electrons into the MDC analysis at the point of impact of each primary beam. A comparison of computed and measured TWT and MDC performance showed very good agreement. The electrodes of the MDC were fabricated from a particular form of isotropic graphite that was selected for its low secondary electron yield, ease of machinability, and vacuum properties. This MDC was tested (at CW) for more than 1000 hr with negligible degradation in TWT and MDC performances

My Little Lost Irene

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