The regional differences between countries in traffic safety: A cross-cultural study and Turkish Case

Road traffic accidents are a large problem everywhere in the world. However, regional differences in traffic safety between countries are considerable. For example, traffic safety records are much worse in Southern Europe and the Middle East than in Northern and Western Europe. Despite the large regional differences in traffic safety, factors contributing to different accident risk figures in different countries and regions have remained largely unstudied. The general aim of this study was to investigate regional differences in traffic safety between Southern European/Middle Eastern (i.e., Greece, Iran, Turkey) and Northern/Western European (i.e., Finland, Great Britain, The Netherlands) countries and to identify factors related to these differences. We conducted seven sub-studies in which I applied a traffic culture framework, including a multi-level approach, to traffic safety. We used aggregated level data (national statistics), surveys among drivers, and data on traffic accidents and fatalities in the analyses. In the first study, we investigated the influence of macro level factors (i.e., economic, societal, and cultural) on traffic safety across countries. The results showed that a high GNP per capita and conservatism correlated with a low number of traffic fatalities, whereas a high degree of uncertainty avoidance, neuroticism, and egalitarianism correlated with a high number of traffic fatalities. In the second, third, and fourth studies, we examined whether the conceptualisation of road user characteristics (i.e., driver behaviour and performance) varied across traffic cultures and how these factors determined overall safety, and the differences between countries in traffic safety. The results showed that the factorial agreement for driver behaviour (i.e., aggressive driving) and performance (i.e., safety skills) was unsatisfactory in Greece, Iran, and Turkey, where the lack of social tolerance and interpersonal aggressive violations seem to be important characteristics of driving. In addition, we found that driver behaviour (i.e., aggressive violations and errors) mediated the relationship between culture/country and accidents. Besides, drivers from "dangerous" Southern European countries and Iran scored higher on aggressive violations and errors than did drivers from "safe" Northern European countries. However, "speeding" appeared to be a "pan-cultural" problem in traffic. Similarly, aggressive driving seems largely depend on road users' interactions and drivers' interpretation (i.e., cognitive biases) of the behaviour of others in every country involved in the study. Moreover, in all countries, a risky general driving style was mostly related to being young and male. The results of the fifth and sixth studies showed that among young Turkish drivers, gender stereotypes (i.e., masculinity and femininity) greatly influence driver behaviour and performance. Feminine drivers were safety-oriented whereas masculine drivers were skill-oriented and risky drivers. Since everyday driving tasks involve not only erroneous (i.e., risky or dangerous driving) or correct performance (i.e., normal habitual driving), but also "positive" driver behaviours, we developed a reliable scale for measuring "positive" driver behaviours among Turkish drivers in the seventh study. Consequently, I revised Reason's model [Reason, J. T., 1990. Human error. Cambridge University Press: New York] of aberrant driver behaviour to represent a general driving style, including all possible intentional behaviours in traffic while evaluating the differences between countries in traffic safety. The results emphasise the importance of economic, societal and cultural factors, general driving style and skills, which are related to exposure, cognitive biases as well as age, sex, and gender, in differences between countries in traffic safety.

Spatial ecology of a specialist insect herbivore : the leaf-mining moth Tischeria ekebladella on the pedunculate oak Quercus robur

Herbivorous insects comprise a major part of terrestrial biodiversity, and their interactions with their host plants and natural enemies are of vast ecological importance. A large body of research demonstrates that the ecology and evolution of these insects may be affected by trophic interactions, by abiotic influences, and by intraspecific processes, but so far research on these individual aspects has rarely been combined. This thesis uses the leaf-mining moth Tischeria ekebladella and the pedunculate oak (Quercus robur) as a case study to assess how spatial variation in trophic interactions and the physical distribution of host trees jointly affect the distribution, dynamics and evolution of a host-specific herbivore. With respect to habitat quality, Tischeria ekebladella experiences abundant variation at several spatial scales. Most of this variation occurs at small scales notably among leaves and shoots within individual trees. While hypothetically this could cause moths to evolve an ability to select leaves and shoots of high quality, I did not find any coupling between female preference and offspring performance. Based on my studies on temporal variation in resource quality I therefore propose that unpredictable temporal changes in the relative rankings of individual resource units may render it difficult for females to predict the fate of their developing offspring. With respect to intraspecific processes, my results suggest that limited moth dispersal in relation to the spatial distribution of oak trees plays a key role in determining the regional distribution of Tischeria ekebladella. The distribution of the moth is aggregated at the landscape level, where local leaf miner populations are less likely to be present where oaks are scarce. A modelling exercise based on empirical dispersal estimates revealed that the moth population on Wattkast an island in south-western Finland is spatially structured overall, but that the relative importance of local and regional processes on tree-specific moth dynamics varies drastically across the landscape. To conclude, my work in the oak-Tischeria ekebladella system demonstrates that the local abundance and regional distribution of a herbivore may be more strongly influenced by the spatial location of host trees than by their relative quality. Hence, it reveals the importance of considering spatial context in the study of herbivorous insects, and forms a bridge between the classical fields of plant-insect interactions and spatial ecology.

Reproduction and population structure in European aspen

The European aspen (Populus tremula) is a keystone species for biodiversity in boreal forests. However, the future of aspen may be threatened, because large aspens have mostly been removed from managed forests, whereas regeneration and the long-term persistence of mature trees are subjects of concern in protected areas. Aspen is a pioneer tree, and it can reproduce both sexually by seed and asexually by root suckers. Through asexual reproduction aspen forms clones, groups of genetically identical trees (ramets). In my thesis, I have studied the structure of aspen populations in terms of number, size, clonal and demographic properties. Additionally, I have investigated the emergence and survival of seedlings as well as the seed quantity and quality in crosses between the European and hybrid aspen. To study the regeneration and population structure, mature aspens were recorded in old-growth and managed forests in eastern Finland based on a large-scale inventory (11 400 ha). In addition, small aspen trees were surveyed on sample plots. Clonal structure was investigated both by morphological characters and by DNA-based markers (microsatellites). Seedling emergence and survival was studied with two sowing experiments. With crosses between European and hybrid aspens we wanted to study whether elevated temperatures due to climate change would benefit the different crosses of European and hybrid aspen unequally and thus affect the gene flow between the two species. The average volumes of mature aspen were 5.3 m3/ha in continuous old-growth, and 0.8 m3/ha in managed forests. Results indicate also that large aspen trees in managed forests are a legacy of the past less intensively managed forest landscapes. Long-term persistence of aspen in protected areas can only be secured by restoration measures creating sufficiently large gaps for regeneration. More emphasis should be given to sparing aspens in thinnings and to retaining of mature aspens in regeneration cutting in managed forests. Aspen was found to be spatially aggregated in the landscape. This could be explained by site type, disturbance history and / or limitations in seed dispersal. Clonal structure does not explain the spatial aggregation, since average size of the clones was only 2.3 ramets, and most clones (70 %) consisted of just one ramet. The small size of the clones suggests that most of them are relatively young. Therefore, sexual reproduction may be more common than has previously been thought. Seedling emergence was most successful in mineral soil especially, when the site had been burned. Only few seedlings occurred on humus. Survival of the seedlings was low, and strongly dependent on moisture, but also on seedbed conditions. The seeds were found to maintain their germinability longer than has earlier been thought to be possible. Interspecific crosses produced more seeds with higher quality than intraspecific crosses. When temperature was elevated, germination of hybrid aspen seeds increased more than seeds from P. tremula x P. tremula crosses. These results suggest that hybrid aspen may have a significant genetic impact on the European aspen, and this effect may become strengthened by climate warming.

Tuloverotuksen reaalinen muuttuminen Suomessa : Kuusikymmentä vuotta verojen vuoristorataa

The study seeks to find out whether the real burden of the personal taxation has increased or decreased. In order to determine this, we investigate how the same real income has been taxed in different years. Whenever the taxes for the same real income for a given year are higher than for the base year, the real tax burden has increased. If they are lower, the real tax burden has decreased. The study thus seeks to estimate how changes in the tax regulations affect the real tax burden. It should be kept in mind that the progression in the central government income tax schedule ensures that a real change in income will bring about a change in the tax ration. In case of inflation when the tax schedules are kept nominally the same will also increase the real tax burden. In calculations of the study it is assumed that the real income remains constant, so that we can get an unbiased measure of the effects of governmental actions in real terms. The main factors influencing the amount of income taxes an individual must pay are as follows: - Gross income (income subject to central and local government taxes). - Deductions from gross income and taxes calculated according to tax schedules. - The central government income tax schedule (progressive income taxation). - The rates for the local taxes and for social security payments (proportional taxation). In the study we investigate how much a certain group of taxpayers would have paid in taxes according to the actual tax regulations prevailing indifferent years if the income were kept constant in real terms. Other factors affecting tax liability are kept strictly unchanged (as constants). The resulting taxes, expressed in fixed prices, are then compared to the taxes levied in the base year (hypothetical taxation). The question we are addressing is thus how much taxes a certain group of taxpayers with the same socioeconomic characteristics would have paid on the same real income according to the actual tax regulations prevailing in different years. This has been suggested as the main way to measure real changes in taxation, although there are several alternative measures with essentially the same aim. Next an aggregate indicator of changes in income tax rates is constructed. It is designed to show how much the taxation of income has increased or reduced from one year to next year on average. The main question remains: How aggregation over all income levels should be performed? In order to determine the average real changes in the tax scales the difference functions (difference between actual and hypothetical taxation functions) were aggregated using taxable income as weights. Besides the difference functions, the relative changes in real taxes can be used as indicators of change. In this case the ratio between the taxes computed according to the new and the old situation indicates whether the taxation has become heavier or easier. The relative changes in tax scales can be described in a way similar to that used in describing the cost of living, or by means of price indices. For example, we can use Laspeyres´ price index formula for computing the ratio between taxes determined by the new tax scales and the old tax scales. The formula answers the question: How much more or less will be paid in taxes according to the new tax scales than according to the old ones when the real income situation corresponds to the old situation. In real terms the central government tax burden experienced a steady decline from its high post-war level up until the mid-1950s. The real tax burden then drifted upwards until the mid-1970s. The real level of taxation in 1975 was twice that of 1961. In the 1980s there was a steady phase due to the inflation corrections of tax schedules. In 1989 the tax schedule fell drastically and from the mid-1990s tax schedules have decreased the real tax burden significantly. Local tax rates have risen continuously from 10 percent in 1948 to nearly 19 percent in 2008. Deductions have lowered the real tax burden especially in recent years. Aggregate figures indicate how the tax ratio for the same real income has changed over the years according to the prevailing tax regulations. We call the tax ratio calculated in this manner the real income tax ratio. A change in the real income tax ratio depicts an increase or decrease in the real tax burden. The real income tax ratio declined after the war for some years. In the beginning of the 1960s it nearly doubled to mid-1970. From mid-1990s the real income tax ratio has fallen about 35 %.

Three Essays on the Volatility of Finnish Stock Returns (summary section only)

First, in Essay 1, we test whether it is possible to forecast Finnish Options Index return volatility by examining the out-of-sample predictive ability of several common volatility models with alternative well-known methods; and find additional evidence for the predictability of volatility and for the superiority of the more complicated models over the simpler ones. Secondly, in Essay 2, the aggregated volatility of stocks listed on the Helsinki Stock Exchange is decomposed into a market, industry-and firm-level component, and it is found that firm-level (i.e., idiosyncratic) volatility has increased in time, is more substantial than the two former, predicts GDP growth, moves countercyclically and as well as the other components is persistent. Thirdly, in Essay 3, we are among the first in the literature to seek for firm-specific determinants of idiosyncratic volatility in a multivariate setting, and find for the cross-section of stocks listed on the Helsinki Stock Exchange that industrial focus, trading volume, and block ownership, are positively associated with idiosyncratic volatility estimates––obtained from both the CAPM and the Fama and French three-factor model with local and international benchmark portfolios––whereas a negative relation holds between firm age as well as size and idiosyncratic volatility.

Executive Stock Options: Exercise Policy and Market Reaction

In this paper I investigate the exercise policy, and the market reaction to that, of the executive stock option holders in Finland. The empirical tests are conducted with aggregated firm level data from 34 firms and 41 stock option programs. I find some evidence of an inverse relation between the exercise intensity of the options holders and the future abnormal return of the company share price. This finding is supported by the view that information about future company prospect seems to be the only theoretical attribute that could delay the exercise of the options. Moreover, a high concentration of exercises in the beginning of the exercise window is predicted and the market is expected to react to deviations from this. The empirical findings however show that the market does not react homogenously to the information revealed by the late exercises.

Performance Persistence of International Stock Funds

People saving in mutual funds often look at historical performance before they decide which funds to invest in. The implicit assumption made is that superior performance is likely to be repeated in the future. The findings presented in this study, which investigates funds sold on the Swedish market, support such an approach provided that the time horizons are limited to one year. International stock funds that have performed strongly one year are likely to outperform their peers also the following years. But if the historical and future time horizons are extended to two or three years, the positive relationship between past and future performance vanishes in most cases. Persistence tests focusing on the aggregated performance of fund companies were also carried out. These tests produced results rather similar to those on the individual fund level.

Porsastuotannon tuottavuuskehitys sikatilinpäätöstiloilla vuosina 2003–2008

Tutkimuksessa mitataan porsastuotannon tuottavuuden kehitystä ProAgrian sikatilinpäätöstiloilla vuosina 2003–2008. Tuottavuutta mitataan Fisher-tuottavuusindeksillä, joka dekomponoidaan tekniseen, allokatiiviseen ja skaalatehokkuuteen sekä teknologiseen kehitykseen ja hintavaikutukseen. Koko aineistosta aggregoidulla tuottavuusindeksillä mitattuna tuottavuus kasvoi viidessä vuodessa yhteensä 14,3 % vuotuisen kasvun ollessa 2,7 %. Tuottajien keskimääräinen tuottavuusindeksi antaa lähes saman tuloksen: sen mukaan tuottavuus kasvaa yhteensä 14,7 %, mikä tekee 2,8 % vuodessa. Skaalatehokkuuden paraneminen havaitaan merkittävimmäksi tuottavuuskasvun lähteeksi. Skaalatehokkuus paranee aggregoidusti mitattuna 1,6 % vuodessa ja tiloilla keskimäärin 2,1 % vuodessa. Teknisen tehokkuuden koheneminen on toinen tuottavuuskasvua edistävä tekijä tutkimusjaksolla. Molemmilla mittaustavoilla nousu on keskimäärin 1,4 % vuodessa. Allokatiivinen tehokkuus laskee hieman: aggregoidusti mitattuna 0,1 % ja keskimäärin 0,4 % vuodessa. Teknologinen kehitys tutkimusjaksolla on lievästi negatiivista, keskimäärin -0,1 % vuodessa. Vuosittaiset vaihtelut ovat kuitenkin voimakkaita. Hintojen muutokset eivät juuri ole vaikuttaneet tuottavuuden tasoon, sillä hintavaikutuksen vuotuiset muutokset jäävät jokaisena vuonna alle puoleen prosenttiin ja keskimääräinen vuotuinen muutos on -0,1 %. Keskeinen tuottavuuskasvua edistänyt tekijä näyttää olleen tilakoon kasvu, joka on parantanut rakenteellista tehokkuutta. Teknologisen kehityksen jääminen negatiiviseksi kuitenkin tarkoittaa, että paras havaittu tuottavuuden taso ei ole noussut lainkaan.

Dynamic Factor Models and Forecasting Finnish Macroeconomic Variables

In recent years, thanks to developments in information technology, large-dimensional datasets have been increasingly available. Researchers now have access to thousands of economic series and the information contained in them can be used to create accurate forecasts and to test economic theories. To exploit this large amount of information, researchers and policymakers need an appropriate econometric model.Usual time series models, vector autoregression for example, cannot incorporate more than a few variables. There are two ways to solve this problem: use variable selection procedures or gather the information contained in the series to create an index model. This thesis focuses on one of the most widespread index model, the dynamic factor model (the theory behind this model, based on previous literature, is the core of the first part of this study), and its use in forecasting Finnish macroeconomic indicators (which is the focus of the second part of the thesis). In particular, I forecast economic activity indicators (e.g. GDP) and price indicators (e.g. consumer price index), from 3 large Finnish datasets. The first dataset contains a large series of aggregated data obtained from the Statistics Finland database. The second dataset is composed by economic indicators from Bank of Finland. The last dataset is formed by disaggregated data from Statistic Finland, which I call micro dataset. The forecasts are computed following a two steps procedure: in the first step I estimate a set of common factors from the original dataset. The second step consists in formulating forecasting equations including the factors extracted previously. The predictions are evaluated using relative mean squared forecast error, where the benchmark model is a univariate autoregressive model. The results are dataset-dependent. The forecasts based on factor models are very accurate for the first dataset (the Statistics Finland one), while they are considerably worse for the Bank of Finland dataset. The forecasts derived from the micro dataset are still good, but less accurate than the ones obtained in the first case. This work leads to multiple research developments. The results here obtained can be replicated for longer datasets. The non-aggregated data can be represented in an even more disaggregated form (firm level). Finally, the use of the micro data, one of the major contributions of this thesis, can be useful in the imputation of missing values and the creation of flash estimates of macroeconomic indicator (nowcasting).

Kirjallisuusosa: Alzheimerin taudin rottamallien vastaavuus tautiin ihmisessä ja mallien käyttökelpoisuus

Kirjallisuusosa: Alzheimerin taudin hoitoon olisi tarvetta uusille taudinkulkuun vaikuttaville lääkeaineille. Niiden kehittämiseksi tarvitaan eläinmalleja, joissa esiintyy taudin patofysiologisia piirteitä. Rottamalleista vanhemmat skopolamiini- tai MK-801-häirintä sekä ikääntyneiden rottien käyttö eivät kovin hyvin vastaa taudin patofysiologiaa, vaikka niissä eläimen muisti käyttäytymiskokeissa onkin heikentynyt. Uudemmat transgeeniset rottamallit ja mallit, joissa annetaan Aβ:a aivoihin, ilmentävät huomattavasti paremmin Alzheimerin taudin kaltaista tilaa aivoissa ainakin Aβ:n osalta. Taupatofysiologiaa ei silti kummassakaan näistä malleista juuri esiinny. Toisaalta Aβ:lla näyttäisi olevan huomattavasti tau:ta suurempi rooli taudissa, joten sen ilmeneminen mallissa onkin keskeisempi tekijä. Nämä mallit ilmentävät melko suurelti osin yhtä hyvin Alzheimerin taudin patofysiologiaa. Aβ:n antaminen on hieman yksinkertaisempi suorittaa käytännössä, sillä siinä ei tarvitse luoda transgeenista kantaa. Toisaalta transgeenisessa mallissa Aβ-patofysiologia syntyy enemmän Alzheimerin taudin kaltaisesti solujen sisällä eikä valmiita aggregoituvia Aβ-peptidejä anneta ulkopuolelta aivoihin. Molemmat mallit ovat kuitenkin käyttökelpoisia, ja soveltuvat erityisesti Aβ:an vaikuttavien lääkeaineiden kehittämiseen. Kokeellinen osa: Kokeen tarkoituksena oli validoida kohotettu ristikko-sokkelo (elevated plus-maze, EPM) hiirillä kognitiomallina. Kokeessa käytettiin kahden koekerran (trial, T) menetelmää, jossa koekertojen pituus oli viisi minuuttia. Näin saatiin useita oppimista kuvaavia parametreja. Hiirille yritettiin saada muistihäiriö aikaviiveen avulla (koekertojen väli 1-18 vrk) tai antamalla muskariinireseptoriantagonistia skopolamiinia (0,1-0,8 mg/kg i.p.) 30 minuuttia ennen T1:tä. Nämä kokeet suoritettiin sekä C57BL/6J- että ICR:(CD-1)-hiirillä. Aikaviivekokeissa ainut ryhmä, jolla oli viitettä unohtamisesta, oli ICR:(CD-1)-hiirien 18 vrk:n ryhmä. Tämän perusteella tutkittiin vielä 21 vuorokauden aikaväli, mutta selvää muistihäiriötä ei esiintynyt. Skopolamiini ei häirinnyt muistia ICR:(CD-1)-hiirillä, mutta C57BL/6J-hiirillä 0,2 mg/kg:n annoksesta ylöspäin merkitsevä muistihäiriö esiintyi. Näin ollen jatkokokeissa käytettäväksi valittiin skopolamiinin annos 0,2 mg/kg C57BL/6J-hiirillä, ja siinä tutkittiin donepetsiilin (0,3, 0,8 ja 1,5 mg/kg s.c), memantiinin (5,0 ja 10,0 mg/kg s.c) ja kokeellisen 5-HT6-antagonistin SB742457:n (1,5 ja 6,0 mg/kg s.c) muistia parantavia vaikutuksia. Tutkittavat lääkeaineet annettiin 40 minuuttia ennen T1:tä ja skopolamiini 30 minuuttia ennen. Memantiinilla (5,0 mg/kg) oli selkeä skopolamiinin heikentämää kognitiota parantava vaikutus ja donepetsiilillakin (1,5 mg/kg) suuntaus tähän. Tulosten perusteella malli näyttäisi soveltuvan muisti- ja oppimisvaikutusten tutkimiseen käytettäväksi malliksi.