Like milk or wine: Does firm performance improve with age?

Our empirical literature review shows that little is known about how firm performance changes with age, presumably because of the paucity of data on firm age. For Spanish manufacturing firms, we analyse the firm performance related to firm age between 1998 and 2006. We find evidence that firms improve with age, because ageing firms are observed to have steadily increasing levels of productivity, higher profits, larger size, lower debt ratios, and higher equity ratios. Furthermore, older firms are better able to convert sales growth into subsequent growth of profits and productivity. On the other hand, we also found evidence that firm performance deteriorates with age. Older firms have lower expected growth rates of sales, profits and productivity, they have lower profitability levels (when other variables such as size are controlled for), and also that they appear to be less capable to convert employment growth into growth of sales, profits and productivity. Keywords: firm age, firm growth, LAD, financial structure, vector autoregression JEL CODES: L25, L20

Water Management Performance in the NIHPSS Summary Report (PDF 635 KB)

Summary Report September 1996

Performance on a Virtual Reality Angled Laparoscope Task Correlates with Spatial Ability of Trainees

The aim of the present study was to investigate whether trainees' performance on a virtual reality angled laparoscope navigation task correlates with scores obtained on a validated conventional test of spatial ability. 56 participants of a surgery workshop performed an angled laparoscope navigation task on the Xitact LS 500 virtual reality Simulator. Performance parameters were correlated with the score of a validated paper-and-pencil test of spatial ability. Performance at the conventional spatial ability test significantly correlated with performance at the virtual reality task for overall task score (p < 0.001), task completion time (p < 0.001) and economy of movement (p = 0.035), not for endoscope travel speed (p = 0.947). In conclusion, trainees' performance in a standardized virtual reality camera navigation task correlates with their innate spatial ability. This VR session holds potential to serve as an assessment tool for trainees.

Organizational form and business performance

This project deals with the generation of profitability and the distribution of its benefits. Inspired by Davis (1947, 1955), we define profitability as the ratio of revenue to cost. Profitability is not as popular a measure of business financial performance as profit, the difference between revenue and cost. Regardless of its popularity, however, profitability is surely a useful financial performance measure. Our primary objective in this project is to identify the factors that generate change in profitability. One set of factors, which we refer to as sources, consists of changes in quantities and prices of outputs and inputs. Individual quantity changes aggregate to the overall impact of quantity change on profitability change, which we call productivity change. Individual price changes aggregate to the overall impact of price change on profitability change, which we call price recovery change. In this framework profitability change consists exclusively of productivity change and price recovery change. A second set of factors, which we refer to as drivers, consists of phenomena such as technical change, change in the efficiency of resource allocation, and the impact of economies of scale. The ability of management to harness these factors drives productivity change, which is one component of profitability change. Thus the term sources refers to quantities and prices of individual outputs and inputs, whose changes influence productivity change or price recovery change, either of which influences profitability change. The term drivers refers to phenomena related to technology and management that influence productivity change (but not price recovery change), and hence profitability change.

Water Management Performance in NIHPSS Follow Up Report (PDF 638 KB)

Report Published December 1998

Does falls efficacy predict gait performance in high-functioning older people?

Introduction: Falls efficacy, defined as confidence in performing activities without falling, is a measure of fear of falling associated with gait impairment, falls and functional decline in frail older people. This relationship has not been well studied in high-functioning older people. Objective: To evaluate the relationship between falls efficacy and gait performance in a cohort of high-functioning older people. Methods: Subjects (N = 864) were a subsample of communitydwelling older people aged 65 to 70 years, enrolled in the "Lc65+" cohort, who completed gait assessment at baseline. Data were collected on demographics, functional, cognitive, affective, and health status. Falls efficacy was assessed using the Falls Efficacy Scale- International (FES-I) that measures confidence in performing 16 activities of daily life (ADL) without falling (score from 16 to 64, higher score indicates lower confidence). Gait parameters were measured over a 20 m walk at preferred gait speed using Physilog, an ambulatory gait monitoring system. Results: Participants (mean age 68.0 ± 1.4 years, 55.0% women) had excellent physical (92.2% independent in basic ADL, mean gait speed 1.13 ± 0.16 m/sec) and cognitive (98.0% with MMSE 024) performance. Nevertheless, 22.1% reported depressive symptoms and 16.1% one or more fall in the previous year. Mean FES-I score was 18.8 ± 4.1. Falls efficacy was associated with gait speed (Spearman rho -0.23, P <.001) and gait variability (Spearman rho 0.10, P = .006), measured by the coefficient of variation of stride velocity. These associations remained in multivariate analysis for both gait speed (adj [beta] coeff: -0.008, 95%CI -0.005 to -0.010, P <.001) and gait variability (adj [beta] coeff 0.024, 95%CI 0.003 to 0.045, P = .023) independent of gender, falls, functional, affective, cognitive, and frailty (Fried's criteria) status. On average, compared to subjects with poor confidence in performing one ADL without falling, those with full confidence had a 0.02 m/sec (2%) faster gait speed and a 2% decrease in gait variability. Conclusion: Even in high-functioning older people, poor falls efficacy is associated with reduced gait speed and stability, independent of health, functional, and frailty status. The direction of this relationship needs to be investigated prospectively to determine causality and design interventions to improve gait performance, reduce fall risk, and prevent functional decline.

Forensic examination of ink by high-performance thin layer chromatography - The United States Secret Service Digital Ink Library

Forensic examinations of ink have been performed since the beginning of the 20th century. Since the 1960s, the International Ink Library, maintained by the United States Secret Service, has supported those analyses. Until 2009, the search and identification of inks were essentially performed manually. This paper describes the results of a project designed to improve ink samples' analytical and search processes. The project focused on the development of improved standardization procedures to ensure the best possible reproducibility between analyses run on different HPTLC plates. The successful implementation of this new calibration method enabled the development of mathematical algorithms and of a software package to complement the existing ink library.

Genetic variability in Brazilian populations of Biomphalaria straminea complex detected by simple sequence repeat anchored polymerase chain reaction amplification

Biomphalaria glabrata, B. tenagophila and B. straminea are intermediate hosts of Schistosoma mansoni, in Brazil. The latter is of epidemiological importance in the northwest of Brazil and, due to morphological similarities, has been grouped with B. intermedia and B. kuhniana in a complex named B. straminea. In the current work, we have standardized the simple sequence repeat anchored polymerase chain reaction (SSR-PCR) technique, using the primers (CA)8RY and K7, to study the genetic variability of these species. The similarity level was calculated using the Dice coefficient and genetic distance using the Nei and Li coefficient. The trees were obtained by the UPGMA and neighbor-joining methods. We have observed that the most related individuals belong to the same species and locality and that individuals from different localities, but of the same species, present clear heterogeneity. The trees generated using both methods showed similar topologies. The SSR-PCR technique was shown to be very efficient in intrapopulational and intraspecific studies of the B. straminea complex snails.

Diagnostic performance characteristics of rapid dipstick test for Plasmodium vivax malaria

We compared the diagnostic performance characteristics of newly developed method, the rapid dipstick test, which provides colorimetric determination by developing antibody to the lactate dehydrogenase enzyme of parasites, with conventional standard thick-blood film examination. For the rapid test, OptiMAL commercial kits were used. The results were also evaluated with clinical findings from patients. The parasites were determined by microscopic examination of thick-blood films from 81 patients with vivax malaria from southeastern Anatolia, Turkey. The OptiMAL test results were found to be negative in five patients who were diagnosed clinically and through thick-film testing as having vivax malaria. There was no false positivity observed with the OptiMAL test. We concluded that this rapid malaria test has a lower level of sensitivity than the classical thick-blood-film test for malaria, but that these methods have equal specificity.

Differentiation and genetic analysis of Rhodnius prolixus and Rhodnius colombiensis by rDNA and RAPD amplification

Domiciliated Rhodnius prolixus and sylvatic R. colombiensis were analyzed in order to confirm their genetic divergence and verify the risk that the latter represents in the domiciliation process, and to provide tools for identifying the sources of possible reinfestation by triatomines in human dwellings allowing control programs to be undertaken. Comparison of random amplified polymorphic DNA amplification patterns and cluster analysis suggests reproductive discontinuity between the two species. The calculated statistical F value of 0.24 and effective migration rate of 0.6 individuals per generation are insufficient to maintain genetic homogeneity between them and confirm the absence of present genetic flow. R. colombiensis presents higher intrapopulation variability. Polymerase chain reaction of ribosomal DNA supports these findings. The low genetic flow between the two species implies that R. colombiensis do not represent an epidemiological risk for the domiciliary transmission of Trypanosoma cruzi in the Tolima Department. The lower variability of the domiciliated R. prolixus could result in greater susceptibility to the use of pesticides in control programs.

Performance Tables 1999-2000 (20/12/00) (PDF 155 KB)

Performance Tables 1999-2000 (20/12/00)