The Permanent Income Hypothesis: A Test on Czech Privatisation

Since the late eighties, economists have been regarding the transition from command to market economies in Central and Eastern Europe with intense interest. In addition to studying the transition per se, they have begun using the region as a testing ground on which to investigate the validity of certain classic economic propositions. In his research, comprising three articles written in English and totalling 40 pages, Mr. Hanousek uses the so-called "Czech national experiment" (voucher privatisation scheme) to test the permanent income hypothesis (PIH). He took as his inspiration Kreinin's recommendation: "Since data concerning the behaviour of windfall income recipients is relatively scanty, and since such data can constitute an important test of the permanent income hypothesis, it is of interest to bring to bear on the hypothesis whatever information is available". Mr. Hanousek argues that, since the transfer of property to Czech citizens from 1992 to 1994 through the voucher scheme was not anticipated, it can be regarded as windfall income. The average size of the windfall was more than three month's salary and over 60 percent of the Czech population received this unexpected income. Furthermore, there are other reasons for conducting such an analysis in the Czech Republic. Firstly, the privatisation process took place quickly. Secondly, both the economy and consumer behaviour have been very stable. Thirdly, out of a total population of 10 million Czech citizens, an astonishing 6 million, that is, virtually every household, participated in the scheme. Thus Czech voucher privatisation provides a sample for testing the PIH almost equivalent to a full population, thus avoiding problems with the distribution of windfalls. Compare this, for instance with the fact that only 4% of the Israeli urban population received personal restitution from Germany, while the number of veterans who received the National Service Life Insurance Dividends amounted to less than 9% of the US population and were concentrated in certain age groups. But to begin with, Mr. Hanousek considers the question of whether the public percieves the transfer from the state to individual as an increase in net wealth. It can be argued that the state is only divesting itself of assets that would otherwise provide a future source of transfers. According to this argument, assigning these assets to individuals creates an offsetting change in the present value of potential future transfers so that individuals are no better off after the transfer. Mr. Hanousek disagrees with this approach. He points out that a change in the ownership of inefficient state-owned enterprises should lead to higher efficiency, which alone increases the value of enterprises and creates a windfall increase in citizens' portfolios. More importantly, the state and individuals had very different preferences during the transition. Despite government propaganda, it is doubtful that citizens of former communist countries viewed government-owned enterprises as being operated in the citizens' best interest. Moreover, it is unlikely that the public fully comprehended the sophisticated links between the state budget, state-owned enterprises, and transfers to individuals. Finally, the transfers were not equal across the population. Mr. Hanousek conducted a survey on 1263 individuals, dividing them into four monthly earnings categories. After determining whether the respondent had participated in the voucher process, he asked those who had how much of what they received from voucher privatisation had been (a) spent on goods and services, (b) invested elsewhere, (c) transferred to newly emerging pension funds, (d) given to a family member, and (e) retained in their original form as an investment. Both the mean and the variance of the windfall rise with income. He obtained similar results with respect to education, where the mean (median) windfall for those with a basic school education was 13,600 Czech Crowns (CZK), a figure that increased to 15,000 CZK for those with a high school education without exams, 19,900 CZK for high school graduates with exams, and 24,600 CZK for university graduates. Mr. Hanousek concludes that it can be argued that higher income (and better educated) groups allocated their vouchers or timed the disposition of their shares better. He turns next to an analysis of how respondents reported using their windfalls. The key result is that only a relatively small number of individuals reported spending on goods. Overall, the results provide strong support for the permanent income hypothesis, the only apparent deviation being the fact that both men and women aged 26 to 35 apparently consume more than they should if the windfall were annuitised. This finding is still fully consistent with the PIH, however, if this group is at a stage in their life-cycle where, without the windfall, they would be borrowing to finance consumption associated with family formation etc. Indeed, the PIH predicts that individuals who would otherwise borrow to finance consumption would consume the windfall up to the level equal to the annuitised fraction of the increase in lifetime income plus the full amount of the previously planned borrowing for consumption. Greater consumption would then be financed, not from investing the windfall, but from avoidance of future repayment obligations for debts that would have been incurred without the windfall.

Injuries to permanent teeth. Part 3: Therapy of root fractures

Diagnostic and therapeutic interventions following dental injuries are not part of the routine practice in the dental office. Quite often, these patients are emergency cases who seek treatment after normal office hours. The objective of this and the future papers is to present the current treatment concepts in dental traumatology at the School of Dental Medicine, University of Berne. The fruitful cooperation in the field of dental traumatology between the Department of Oral Surgery and Stomatology, and the Department of Conservative Dentistry (including pediatric dentistry and endodontology), is based on the interdisciplinary approach that has been established four years ago. Following discussion and evaluation of such treated cases, and considering current clinical and experimental studies, the said concepts have been worked out. The present paper describes the therapeutic approach for root fractures.

Guidelines for the management of traumatic dental injuries. II. Avulsion of permanent teeth

Avulsion of permanent teeth is the most serious of all dental injuries. The prognosis depends on the measures taken at the place of accident or the time immediately after the avulsion. Replantation is the treatment of choice, but cannot always be carried out immediately. An appropriate emergency management and treatment plan is important for a good prognosis. Guidelines are useful for delivering the best care possible in an efficient manner. The International Association of Dental Traumatology (IADT) has developed a consensus statement after a review of the dental literature and group discussions. Experienced researchers and clinicians from various specialties were included in the group. In cases in which the data did not appear conclusive, recommendations were based on the consensus opinion of the IADT board members. The guidelines represent the current best evidence based on literature research and professional opinion. In this second article of three, the IADT Guidelines for management of avulsed permanent teeth are presented.

Guidelines for the management of traumatic dental injuries. I. Fractures and luxations of permanent teeth

Crown fractures and luxations occur most frequently of all dental injuries. An appropriate treatment plan after an injury is important for a good prognosis. Guidelines are useful for delivering the best care possible in an efficient manner. The International Association of Dental Traumatology (IADT) has developed a consensus statement after a review of the dental literature and group discussions. Experienced researchers and clinicians from various specialties were included in the group. In cases where the data did not appear conclusive, recommendations were based on the consensus opinion of the IADT board members. The guidelines represent the current best evidence, based on literature research and professional opinion. In this first article of three, the IADT Guidelines for management of fractures and luxations of permanent teeth will be presented.

[Injuries to permanent teeth--Part 4: Therapy of crown fractures]

Diagnostic and therapeutic interventions following dental injuries are not part of the routine practice in the dental office. Quite often, these patients are emergency cases who seek treatment after normal office hours. The objective of this and the future papers is to present the current treatment concepts in dental traumatology at the School of Dental Medicine, University of Berne. The fruitful cooperation in the field of dental traumatology between the Department of Oral Surgery and Stomatology, and the Department of Conservative Dentistry (including pediatric dentistry and endodontology) is based on the interdisciplinary approach that has been established five years ago. Following discussion and evaluation of such treated cases, and considering current clinical and experimental references, the said concepts have been worked out. The present paper describes the therapeutic concepts of crown fractures.

Pulp and periodontal healing of laterally luxated permanent teeth: results after 4 years

AIM: To evaluate the pulp and periodontal healing of laterally luxated permanent teeth. MATERIAL AND METHODS: Patients presenting with lateral luxation of permanent teeth during 2001-2002 were enrolled in this clinical study. Laterally luxated teeth were repositioned and splinted with a TTS/composite resin splint for 4 weeks. Immediate (prophylactic) root-canal treatment was performed in severely luxated teeth with radiographically closed apices. All patients received tetracycline for 10 days. Re-examinations were performed after 1, 2, 3, 6, 12 and 48 months. RESULTS: All 47 laterally luxated permanent teeth that could be followed over the entire study period survived. In 10 teeth (21.3%), a prophylactic root-canal treatment was performed within 2 weeks following injury. The remaining 37 teeth showed the following characteristics at the 4-year re-examination: 19 teeth (51.4%) had pulp survival (no clinical or radiographic signs or symptoms), nine teeth (24.3%) presented with pulp canal calcification, and pulp necrosis was seen in another nine teeth (24.3%), within the first year after trauma. None of the teeth with a radiographically open apex at the time of lateral luxation showed complications. External root resorption was only seen in one tooth. CONCLUSIONS: Laterally luxated permanent teeth with incomplete root formation have a good prognosis, with all teeth surviving in this study. The most frequent complication was pulp necrosis that was only seen in teeth with closed apices.

Clinical performance of a new laser fluorescence device for detection of occlusal caries lesions in permanent molars

OBJECTIVES: To determine the clinical performance of a laser fluorescence device (DIAGNOdent pen, KaVo) to discriminate between different occlusal caries depths (D(0)-D(1-4); D(0-2)-D(3,4)) in permanent molars. METHODS: In this prospective, randomized two-centre-study 120 sound/uncavitated carious sites in 120 patients were measured after visual and radiographic caries assessment. In cases of operative intervention (n=86), the lesion depths after caries removal were recorded (reference). In cases of preventive intervention (n=34), the sites were reassessed visually/radiographically after 12 months to verify the status assessed before (reference). The discrimination performance was determined statistically (Mann-Whitney test, Spearman's rho coefficient, and areas under the receiver operating characteristic curves (AUCs)). Sensitivities (SE) and specificities (SP) were plotted as a function of the measured values and cut-off values for the mentioned thresholds suggested. RESULTS: Sound sites (n=13) had significantly minor fluorescence values than carious sites (n=107) (P<0.0001) as had sites with no/enamel caries (n=63) compared to dentinal caries (n=57). The AUCs for the same discriminations were 0.92 and 0.78 (P<0.001). For the D(0)-D(1-4) threshold, a cut-off at a value of 12 (SE: 0.88, SP: 0.85) and for the D(0-2)-D(3,4) threshold at 25 (SE: 0.67, SP: 0.79) can be suggested. A moderate positive correlation between the measurements and the caries depths was calculated (rho=+0.57, P=0.01). CONCLUSION: Within this study, the device's discrimination performance for different caries depths was moderate to very good and it may be recommended as adjunct tool in the diagnosis of occlusal caries.

Biolimus-eluting biodegradable polymer versus sirolimus-eluting permanent polymer stent performance in long lesions: results from the LEADERS multicentre trial substudy

AIMS: Lesion length remains a predictor of target lesion revascularisation and results of long lesion stenting remain poor. Sirolimus-eluting stents have been shown to perform better than paclitaxel eluting stents in long lesions. In this substudy of the LEADERS trial, we compared the performance of biolimus biodegradable polymer (BES) and sirolimus permanent polymer stents (SES) in long lesions. METHODS AND RESULTS: A total of 1,707 'all-comer' patients were randomly allocated to treatment with BES and SES. A stratified analysis of angiographic and clinical outcomes at nine months and one year, respectively was performed for vessels with lesion length <20 mm versus >20 mm (as measured by quantitative angiography).Of 1,707 patients, 592 BES patients with 831 lesions and 619 SES patients with 876 lesions had only short lesions treated. One hundred and fifty-three BES patients with 166 lesions and 151 SES patients with 162 lesions had long lesions. There were no significant differences in baseline clinical characteristics, except for higher number of patients with long lesions presenting with acute myocardial infarction in both stent groups. Long lesions tended to have lower MLD and greater percent diameter stenosis at baseline than short lesions. Late loss was greater for long lesions than short lesions. There was no statistically significant difference in late loss between BES and SES stents (0.32+/-0.69 vs 0.24+/-0.57, p=0.59). Binary in-segment restenosis was present in 23.2% versus 13.1% of long lesions treated with BES and SES, respectively (p=0.042). In patients with long lesions, the overall MACE rate was similar for BES and SES (17% vs 14.6%; p=0.62). There was a trend towards higher overall TLR rate with BES (12.4 % vs 6.0%; HR=2.06; p=0.07) and clinically driven TLR (10.5% vs 5.3%: HR 1.94; p=0.13). Rates of definite stent thrombosis were 3.3% in the long lesion group and 1.3-1.7 % in the short lesion group. CONCLUSIONS: BES and SES appear similar with respect to MACE in long lesions in this "all-comer" patient population. However, long lesions tended to have a higher rate of binary in-segment restenosis and TLR following BES than SES treatment.

Comparison of intraoral radiography and limited cone beam computed tomography for the assessment of root-fractured permanent teeth

AIM: To compare intraoral occlusal (OC) and periapical (PA) radiographs vs. limited cone beam computed tomography (CBCT) in diagnosing root-fractured permanent teeth. MATERIAL AND METHODS: In 38 patients (mean age 24 years, range 8-52 years) with 44 permanent teeth with horizontal root fractures, intraoral radiographs (PA and OC) and limited CBCT were used to evaluate the location (apical, middle, cervical third of the root) and angulation of the fracture line. Furthermore, the conventional radiographs and CBCT images were compared for concordance of fracture location. RESULTS: In the PA and OC radiographs, 28 fractures (63.6%) were located in the middle third of the root, 11 (25.0%) in the apical third and 5 (11.4%) in the cervical third. The PA/OC radiographs and the sagittal CBCT images (facial aspect) yielded the same level of root fracture in 70.5% of cases (31 teeth; 95% CI: 54.1-82.7%). The PA/OC radiographs and sagittal CBCT images (palatal aspect) showed the same level of root fracture in 31.8% of cases. There was a statistically significant association between the angle at which the root fracture line intersected the axis of the tooth and the level of root fracture in the facial aspect of the sagittal CBCT images. CONCLUSIONS: The diagnosis of the location and angulation of root fractures based on limited CBCT imaging differs significantly from diagnostic procedures based on intraoral radiographs (PA/OC) alone. The clinical significance for treatment strategies and for the prognosis of root-fractured teeth has to be addressed in future studies.