Credit crunches and credit allocation in a model of entrepreneurship

We study the effects of credit shocks in a model with heterogeneous entrepreneurs, financing constraints, and a realistic firm-size distribution. As entrepreneurial firms can grow only slowly and rely heavily on retained earnings to expand the size of their business, we show that, by reducing entrepreneurial firm size and earnings, negative shocks have a very persistent effect on real activity. In determining the speed of recovery from an adverse economic shock, the most important factor is the extent to which the shock erodes entrepreneurial wealth

Credit crunches and credit allocation in a model of entrepreneurship

We study the effects of credit shocks in a model with heterogeneous entrepreneurs, financing constraints, and a realistic firm size distribution. As entrepreneurial firms can grow only slowly and rely heavily on retained earnings to expand the size of their business in this set-up, we show that, by reducing entrepreneurial firm size and earnings, negative shocks have a very persistent effect on real activity. In determining the speed of recovery from an adverse economic shock, the most important factor is the extent to which the shock erodes entrepreneurial wealth

Estate Taxation, Entrepreneurship, and Wealth

This paper studies the estate tax in a quantitative framework with business investment, borrowing constraints, estate transmission, and wealth inequality. We find that the estate tax has little effect on the saving and investment decisions of small businesses, but does distort the decisions of larger firms, thereby reducing aggregate output and savings. Removing such distortions by eliminating the estate tax does not necessarily imply that everyone would be better off. If other taxes were raised to reestablish fiscal balance, those at the top of the wealth distribution would experience a large welfare gain, but most of the population would lose. (JEL D31, E21, H2

Entrepreneurs, Chance, and the Deterministic Concentration of Wealth

In many economies, wealth is strikingly concentrated. Entrepreneurs–individuals with ownership in for-profit enterprises–comprise a large portion of the wealthiest individuals, and their behavior may help explain patterns in the national distribution of wealth. Entrepreneurs are less diversified and more heavily invested in their own companies than is commonly assumed in economic models. We present an intentionally simplified individual-based model of wealth generation among entrepreneurs to assess the role of chance and determinism in the distribution of wealth. We demonstrate that chance alone, combined with the deterministic effects of compounding returns, can lead to unlimited concentration of wealth, such that the percentage of all wealth owned by a few entrepreneurs eventually approaches 100%. Specifically, concentration of wealth results when the rate of return on investment varies by entrepreneur and by time. This result is robust to inclusion of realities such as differing skill among entrepreneurs. The most likely overall growth rate of the economy decreases as businesses become less diverse, suggesting that high concentrations of wealth may adversely affect a country's economic growth. We show that a tax on large inherited fortunes, applied to a small portion of the most fortunate in the population, can efficiently arrest the concentration of wealth at intermediate levels

Performance differences of two potentiometric fluoride determination methods in hard dental tissue

A comparison between two ion selective electrode (ISE) potentiometric methods is reported for determining the amount of fluoride in hard dental tissue after placement of fluoride-releasing dental restorations. The two methods are: (1) the direct method involving linear calibration (LC), and (2) a spiking method involving multiple standard additions (MA). Results showed that measurements performed by the LC method underestimate the amount of fluoride released by up to 30%. Recovery tests demonstrated that the use of MA and blank correction procedures is useful for an accurate and sensitive ISE determination of fluoride in hard dental tissues

The high frequency of spontaneous micronuclei observed in lymphocytes of systemic sclerosis patients: preliminary results

Objective: aim of the study is to assess the presence of spontaneous chromosome damage in patients affected by limited (lSSc) or diffuse (dSSc) Systemic Slerosis, using the micronucleus (MN) assay. Methods: we evaluated MN frequency in cultured peripheral lymphocytes of 18 SSc and in a group of 20 healthy controls. Patients were also classified as ACA+, Scl70+, FAN+ according to the presence of the specific anti-nuclear antibodies. We also explored the hypothesis that the extent of cytogenetic alteration might be related to the severity of the pathological condition and/or to the immunological profile. Results: compared to controls, the patient group as a whole showed significantly higher MN frequencies (10.8±4.5 vs. 27.8±13.7, p<0.001). No correlation was found between spontaneous chromosome damage and severity of the disease, being MN frequency 33.1±17.0 and 19.8±2.7 in lSSc and dSSc, respectively. Interestingly, ACA+ subjects displayed the highest MN frequency (36.9±15.0), as compared to patients with different antibody pattern (Scl70+, FAN+; 19.7±8.2). Conclusions: our results confirm the presence of chromosomal damage in circulating lymphocytes of SSc patients and would suggest a key role of antibodies to the centromere in determining the observed cytogenetic anomalies

The high frequency of spontaneous micronuclei observed in lymphocytes of systemic sclerosis patients: preliminary results.

OBJECTIVE: Aim of the study is to assess the presence of spontaneous chromosome damage in patients affected by limited (lSSc) or diffuse (dSSc) Systemic Slerosis, using the micronucleus (MN) assay.METHODS: We evaluated MN frequency in cultured peripheral lymphocytes of 18 SSc and in a group of 20 healthy controls. Patients were also classified as ACA+, Scl70+, FAN+ according to the presence of the specific anti-nuclear antibodies. We also explored the hypothesis that the extent of cytogenetic alteration might be related to the severity of the pathological condition and/or to the immunological profile.RESULTS: Compared to controls, the patient group as a whole showed significantly higher MN frequencies (10.8+/-4.5 vs. 27.8+/-13.7, p&lt;0.001). No correlation was found between spontaneous chromosome damage and severity of the disease, being MN frequency 33.1+/-17.0 and 19.8+/-2.7 in lSSc and dSSc, respectively. Interestingly, ACA+ subjects displayed the highest MN frequency (36.9+/-15.0), as compared to patients with different antibody pattern (Scl70+, FAN+; 19.7+/-8.2).CONCLUSIONS: Our results confirm the presence of chromosomal damage in circulating lymphocytes of SSc patients and would suggest a key role of antibodies to the centromere in determining the observed cytogenetic anomalies

Does a social/behavioural gradient in dental health exist among adults? A cross-sectional study

Objective To explore the potential presence of a social/behavioural gradient in dental health among Italian adults using a cross-sectional study. Methods Caries indices were recorded among 480 subjects (52.9% men, 47.1% women) who also completed a structured self-administered social and behavioural questionnaire. A social/behavioural gradient was generated as the sum of the worst circumstances recorded on the questionnaire (cariogenic diet, smoking, lowest occupational profile, brushing teeth<twice daily, lowest educational level, uneven dental examination attendance). Results Caries figures (DMFT) and the number of filled sound teeth (FS-T) were statistically significantly linked to the social/behavioural gradient (DMFT: (2)((9))=20.17 p=0.02, Z=0.02 p=0.99; FS-T: (2)((9))=25.68 p<0.01, Z=-4.31 p<0.01). DMFT was statistically significantly associated with gender and with social and behavioural variables. FS-T was higher in women (p=0.03) and was linked to smoking (p<0.01). Conclusions The proposed social/behavioural gradient demonstrated how subjects reporting the worst circumstances on the questionnaire exhibited the worst dental health. The use of the gradient demonstrates that health promotion and prevention cannot be compartmentalized

Chromosome aberrations, valued as frequency of spontaneous micronuclei, in subjects with suspected presclerodermic Raynaud's phenomenon

OBJECTIVE: To evaluate the prevalence of spontaneous chromosome damage in cultured peripheral lymphocytes of subjects with suspected presclerodermic Raynaud's phenomenon (RP), by means of molecular cytogenetic analysis.METHODS: We studied 20 suspected presclerodermic RP, 20 idiopathic RP and 25 healthy subjects. As marker of chromosome alteration we used the micronucleus assay. All subjects were also classified as ANA-, ACA+ or Scl70+. To identify the mechanism of MN formation, a MN fluorescence in situ hybridisation (FISH) analysis using a pancentromeric DNA probe was also performed.RESULTS: Suspected presclerodermic RP subjects, showed significantly higher MN frequencies than idiopathic RP and controls (39+/-15.2 vs 10+/-2.1 and 9.8+/-3.5 respectively p&lt;0.0001). Interestingly, subjects with idiopathic RP displayed MN frequency comparable to that of controls. Furthermore, ACA+ subjects showed the highest MN frequencies (44+/-8.1) as compared to subjects with different antibody pattern (26+/-7.1).CONCLUSIONS: Our results show the presence of higher levels of chromosomal damage in circulating lymphocytes of suspected presclerodermic RP. They also would suggest a key role of anti-centromere antibody in determining the observed cytogenetic anomalies. FISH analysis indicated that both aneuploidogenic and clastogenic events contribute to the formation of MN observed in suspected presclerodermic RP