Herding behavior in the US stock markets : Does market capitalization matter?

Herding behavior has been recognized as a significant factor and phenomenon in investors’ decision-making process. Herding as a concept derives from animals and has analogously been adopted by economists to describe comparable human behavior in financial markets. This phenomenon applies to both individual and institutional investors, the difference being mostly in the causes and effects of the behavior. This thesis aims to sufficiently review recent literature of the herding effect in financial markets and conduct an empirical study that measures the intensity of herding in different equity indices. The empirical testing of the thesis focuses on the S&P 500, S&P 400 MidCap and S&P 600 SmallCap. The goal is to evaluate if the size of market capitalization influences the volume of herding in markets. In addition, a similar comparison is conducted between a value stock index and a growth stock grouping. The paper also introduces the herding concept and reviews its various forms. Particularly compared to more recent literature, the results are at least partially consistent with earlier research. The literature review shows that herding research results have experienced some transformation over time. More recent studies seem to yield more robust evidence of herding. This may be due to enhanced research methods. This study applies the CSAD-model that has received some criticism of its ability to detect herding. Although, at standard statistical levels, and consistent with studies that use the CSAD measure of herding, the full sample testing results of this thesis find no evidence of herding. In contrast to full sample results, statistically significant evidence of herding behavior is found in more focused sample sets. For example, year by year and other data arrangements reveal significant evidence of the occurrence of herd behavior. This study also finds evidence of correlation be-tween herding and volatility. The sample period as a single entity does not reliably show that investors consistently herd toward specific stock characteristics, rather it depends on market conditions. One observation from the results is that investors tend to herd toward large-cap stocks in times of high uncertainty. Tests on large capitalization growth stocks reveal that they have experienced significant herding in the last few years.Laumakäyttäytyminen on tunnustettu merkittäväksi osaksi ja ilmiöksi sijoittajien päätöksentekoprosesseissa. Laumakäyttäytymisen konsepti on saanut alkunsa eläintieteistä, kun tutkijat havainnoivat eläinten taipumusta seurailla toisiaan. Taloustieteilijät käyttävät termiä kuvaamaan sijoittajien verrattain vastaavaa käytöstä, jossa sijoituspäätöksiä tehdään ainoastaan muiden sijoittajien toimien perusteella. Laumakäyttäytymistä ilmenee niin yksityisten kuin institutionaalisten sijoittajien keskuudessa. Tämän tutkielman tarkoitus on käydä kattavasti läpi aiheen teoriaa ja kirjallisuutta, sekä suorittaa empiirinen koe, joka testaa miten laumakäyttäytymistä ilmenee eri markkina-arvojen osakeindekseissä. Empiirisen testin kohdeindeksit ovat S&P 500 (markkina-arvoltaan suurten osakkeiden indeksi), S&P 400 (keskikokoiset), sekä S&P 600 (pienet). Tavoitteena on arvioida, vaikuttaako markkina-arvo lauman liikkeisiin, ts. onko laumoilla (sijoittajilla) taipumus liikkua kohti tietyn markkina-arvon osakkeita. Vastaava vertailu toteutetaan myös suuren markkina-arvon kasvuosakkeiden ja pienempien arvo-osakkeiden välillä. Lisäksi tutkielma esittelee kattavasti laumakäyttäytymistä käyttäytymistaloustiedeiden kontekstissa, sekä käy läpi sen eri muotoja. Tutkimuksen tulokset ovat ainakin osittain linjassa aikaisemman kirjallisuuden kanssa, erityisesti verrattuna uudempiin tutkimuksiin. Kirjallisuuskatsaus osoittaa, että laumakäyttäytymisen mittaustulokset ovat kokeneet jonkin verran muutosta ajan myötä, sillä uudemmat tutkimukset vaikuttaisivat löytävän vahvempaa todistusaineistoa laumakäyttäytymisestä verrattuna vanhempiin tutkimuksiin. Tutkielma käyttää mittaamiseen tutkijoiden keskuudessa verrattain suosittua CSAD-mallia. Malli on saanut osakseen myös jonkin verran kritiikkiä sen käytettävyydestä aiheen mittaamiseen. Tutkielma ei löydä tieteellisesti merkittäviä tuloksia laumakäyttäytymisestä, kun mittauksen kohteena on koko tarkastelujakson data. Tämä on linjassa aiempien tutkimusten kanssa, joiden mittarina on CSAD. Vastaavasti kun mittauksen kohteena käytetään eri datajärjestelyitä, mm. vuosi kerrallaan, sekä viikottainen ja neljännesvuosittainen datajärjestely, tutkielma havaitsee runsaasti tilastollisesti merkitsevää todistusaineistoa laumakäyttäytymisen olemassaolosta. Lisäksi tutkielma havaitsee todisteita merkittävästä korrelaatiosta laumakäyttäytymisen ja volatiliteetin välillä. Kokonaisuutena (koko tarkastelujakson datalla) tutkielma ei kykene luotettavasti osoittaamaan, että sijoittajat liikkuvat johdonmukaisesti ja synkronoidusti kohti tietyn markkina-arvon osakkeita. Lauman liike ja kohde vaikuttaisi riippuvan ennemminkin markkinoiden olosuhteista, sillä mm. yksi havainto on, että sijoittajilla on taipumus allokoida pääomia suuren markkina-arvon osakkeisiin korkean epävarmuuden aikana. Tutkielma osoittaa, että lähes yhtäaikainen liike ei johdu välttämättä fundamentaalisen informaation muutoksista, vaan ennemminkin siitä, että sijoittajat seuraavat toisiaan lauman lailla kohti suuren markkina-arvon osakkeita. Testit suuren markkina-arvon kasvuosakkeille paljastavat, että ne ovat kokeneet merkittävää laumakäyttäytymisestä erityisesti viime vuosien aikana

Ympäristön ja hoitotekijöiden vaikutus emakon lisääntymisen tehokkuuteen huomioiden erityisesti kausilisääntymisen hallinta

Seasonal infertility is well-defined phenomenon in modern swine production. The outcomes mostly affected are age at puberty in gilts, weaning-to-oestrus interval (WOI) and farrowing rate in sows. The European wild boar, the ancestor of our domestic pig, is a distinct short-day seasonal breeder. Photoperiod is thought to be the most important regulating factor in seasonal breeders. In addition to photoperiod, many environmental and management factors are known to adjust the manifestation of seasonal infertility. The aim of this work was to obtain information about the effect of photoperiod on reproductive endocrinology and on reproductive performance. In addition, the effect of re-modelling the piggery breeding unit on farrowing rate was studied. In the first clinical trial (I), two light regimes were tested in experimental conditions. One group of ovariectomized gilts (16 domestic pigs and 4 European wild boars) was kept under short daylight conditions (8-h light, 16-h dark) and the other group under long daylight conditions (16-h light, 8-h dark). After the treatment period, LH secretion patterns were determined by repeated blood sampling. In contrast to our expectations, LH pulse frequency remained unchanged in both light regimes. However, in the domestic pig, mean and basal LH concentrations were higher in the long-day group than in the short-day group. To investigate the two light regimes under more practical conditions, two trials (II, III) were conducted in commercial piggeries. The outcomes were farrowing rate and WOI. In trial II, the long-day group was kept under a constant 16-h light, 8-h dark regime. The short daylight regime consisted of a light phase of 8-h and a dark phase of 16-h in farrowing and breeding units. The length of the short-day treatment was 6 weeks before breeding. In the gestation unit, the short-day animals were also kept under a 16L:8D regime. The results of this trial revealed that the farrowing rate was 90% in both groups, and the two treatment groups also shared the same median WOI, i.e. 5 days. In trial III, the long daylight regime consisted again of a constant long-day treatment. However, the photophase was 14L:10D. The short-day treatment was extended to 8 weeks and took place exclusively in the farrowing unit. The light regime was 10L:14D. The short-day group was also kept under a 14L:10D regime in the breeding and gestation units. Despite these modifications, the results were the same as in the previous trial. The farrowing rate was 90% and median WOI five days in both groups. The last part (IV) of this thesis was an observational retrospective cohort study with a historical control. A cohort of farms with individual cages in their breeding unit was chosen. These farms either remodelled their breeding cages or switched to different group housing systems in the breeding unit. The farrowing rate before and one year after the remodelling was then compared. The remodelling itself was shown to affect reproductive performance on these farms. In conclusion, the reproductive performance of sows is difficult to control by a single environmental (photoperiod) or management (housing strategy) factor.Syyshedelmättömyys on tunnettu ilmiö nykyaikaisessa sianlihan tuotannossa. Ongelmana on porsimisprosentin lasku, pidentynyt aika vieroituksesta kiimaan sekä ensikoiden myöhäinen sukukypsyys loppukesän, syksyn aikana. Tuotantoeläimenä käyttämämme kesysian esi-isä, eurooppalainen villisika, on selkeä lyhyen päivän kausilisääntyjä. Valojaksolla tiedetään olevan merkittävä rooli kausilisääntymisen säätelyssä. Lisäksi muilla ympäristö- ja hoitotekijöillä on osuutta kausilisääntymisen ilmenemisessä. Tämän väitöskirjan tavoitteena oli selvittää valojakson vaikutusta sian lisääntymiseen liittyvään sisäeritykseen sekä tuotostasoon. Lisäksi tutkittiin toisen ympäristötekijän, sikalarakenteen muuttamisen, vaikutusta emakoiden hedelmällisyyteen. Valojakso ja luteinisoivan hormonin eritys kesy- ja villisialla Koesikojen (16 kesy- ja 4 villisikaa) avulla tutkittiin lyhyen ja pitkän päivän valo-ohjelman vaikutusta ensikoiden luteinisoivan hormonin (LH) eritykseen. LH hormoni on merkittävä normaaliin kiimakiertoon ja tiineyden ylläpitoon liittyvä hormoni, jonka liian vähäinen eritys voi aiheuttaa ongelmia lisääntymisessä. Oletuksena tutkimuksessa oli, että lyhyen päivän emakoilla LH eritys on tiheämmin pulsoivaa. LH profiilit eivät kuitenkaan eronneet valo-ohjelmien välillä . LH perustaso ja keskiarvo olivat lyhyen päivän ensikoilla matalammat kuin pitkän päivän ensikoilla. Tutkimusmenetelmiin liittyvät ongelmat voivat vääristää tämän osakokeen tuloksia merkittävästi. Valo-ohjelmien vaikutus emakoiden hedelmällisyyteen ja tuotokseen Valo-ohjelman vaikutusta emakoiden porsimisprosenttiin tutkittiin kahdessa eri kenttäkokeessa sikatiloilla. Molemmissa kokeissa verrattiin lyhyen ja pitkän päivän valaistusta juuri ennen tiineytystä tai tiineytyksen aikana. Kokeiden erona oli ensimmäisen kokeen lyhyempi hoitojakso (6 viikkoa) verrattuna toisen kokeen pidempään (8 viikkoa) hoitojaksoon. Tiineysaikana molemmat ryhmät pidettiin kummassakin kokeessa pitkän päivän valaistuksessa. Oletuksena oli, että lyhyen päivän emakoiden porsimisprosentti olisi korkeampi verrattuna pitkän päivän emakoihin. Porsimisprosentti oli noin 90 prosenttia ja aika vieroituksesta kiimaan 5 päivää (mediaani) molemmissa koeryhmissä, kummassakin osakokeessa. Kumpikaan valo-ohjelma ei siis osoittautunut toista paremmaksi. Sikaloissa, joissa hedelmällisyys on jo lähtökohtaisesti hyvällä tasolla, valo-ohjelman käytöllä on vaikea saavuttaa ekstraetua emakoiden hedelmällisyyden suhteen. Sikalarakenteen vaikutus emakon hedelmällisyyteen ja tuotokseen, retrospektiivinen tutkimus Viimeisessä osaprojektissa kerättiin tietoa tiineytysosaston remontoinnin vaikutuksesta emakoiden hedelmällisyyteen. Projektiin osallistuvat tilat (47) olivat muuttaneet tiineytysosastonsa joutilashäkkimallista erilaisiksi pihatoiksi vuosien 1995 2002 aikana. Tiineytysosaston remontointi ei vaikuttanut tilojen porsimisprosenttiin porsimisprosentit olivat samat ennen ja jälkeen remontin riippumatta pihattotyypistä, johon tiineytysosasto muutettiin. Kuitenkin, jos tilojen hedelmällisyyden lähtötilanne otettiin huomioon, nousi lähtökohtaisesti keskimääräistä heikompien tilojen porsimisprosentti remontin jälkeen ja vastaavasti keskimääräistä parempien tilojen porsimistilanne laski alkutilanteeseen nähden. Yhteenvetona voidaan todeta, että emakon lisääntymisen hallinta yksittäisen ympäristö- tai olosuhdetekijän avulla on vaikeaa

Seasonal alterations in circadian melatonin rhythms of the European wild boar and domestic gilt,

Peer reviewe

Antimicrobial use and susceptibility of indicator Escherichia coli in Finnish integrated pork production

In pigs, antimicrobial use (AMU) practices vary at different production phases between herds and between countries. Antimicrobial resistance (AMR) development is linked to AMU but recognized as a multi-factorial issue, and thus, any information increasing knowledge of AMU and AMR relationships is valuable. We described AMU and screened the carriage of different AMR phenotypes of indicator Escherichia coli in 25 selected Finnish piglet-producing and finishing herds that formed nine birth-to-slaughter production lines. Moreover, we studied associations between AMU and AMR in both herd types and throughout the production line. Treatment records were obtained from the national Sikava register for 1year, and AMU was quantified as mg/PCU (population correction unit) and TIs (treatment incidences). For phenotypic antimicrobial susceptibility testing, ten pen-level pooled feces samples (n=250) in each herd were collected from one room representing the oldest weaned piglets or the oldest finishing pigs. Majority of the medications (96.8%) was administered parenterally, and penicillin was the predominant antimicrobial in every herd. More different antimicrobial substances were used in piglet-producing than in finishing herds (median 5 and 1, respectively, pPeer reviewe

Effect of Farm Management Practices on Morbidity and Antibiotic Usage on Calf Rearing Farms

Antimicrobial resistance has been recognized as one of the top health threats to human society. Abundant use of antibiotics in both humans and animals has led to ever-increasing antibiotic resistance in bacteria. In food production, decreasing morbidity in beef herds would be an effective way to reduce the use of antibiotics. The objective of this retrospective observational study was to determine overall morbidity on calf rearing farms and to identify associated risk factors. Data were collected by questionnaire, meat companies’ databases and the national cattle register for 28,228 calves transported to 87 calf rearing farms. All medications given to these calves were retrospectively followed for 180 days from calf arrival to the farm. In total, 34,532 parenteral antibiotic medications were administered to the 28,228 study calves (122.3%), and 17,180 calves (60.9%) were medicated with antibiotics at least once during the follow-up. Higher numbers of calves transported to the same farm and larger age variation in calves in the same arrival batch were both associated with increased morbidity. In contrast, higher arrival age of individual calves was associated with decreased morbidity. Our study identifies several factors to consider in decreasing morbidity and antibiotic usage on calf rearing farms

Effect of Farm Management Practices on Morbidity and Antibiotic Usage on Calf Rearing Farms

Antimicrobial resistance has been recognized as one of the top health threats to human society. Abundant use of antibiotics in both humans and animals has led to ever-increasing antibiotic resistance in bacteria. In food production, decreasing morbidity in beef herds would be an effective way to reduce the use of antibiotics. The objective of this retrospective observational study was to determine overall morbidity on calf rearing farms and to identify associated risk factors. Data were collected by questionnaire, meat companies’ databases and the national cattle register for 28,228 calves transported to 87 calf rearing farms. All medications given to these calves were retrospectively followed for 180 days from calf arrival to the farm. In total, 34,532 parenteral antibiotic medications were administered to the 28,228 study calves (122.3%), and 17,180 calves (60.9%) were medicated with antibiotics at least once during the follow-up. Higher numbers of calves transported to the same farm and larger age variation in calves in the same arrival batch were both associated with increased morbidity. In contrast, higher arrival age of individual calves was associated with decreased morbidity. Our study identifies several factors to consider in decreasing morbidity and antibiotic usage on calf rearing farms

Effect of farm and animal-level factors on youngstock mortality and growth on calf rearing farms

Both calf mortality and daily weight gain have a crucial impact on profitability of calf rearing farms. In addition, high calf mortality rates represent an animal welfare problem. Mortality rates on calf rearing farms have been reported in several studies in different countries, but scant data regarding daily weight gain of the calves are available. The objectives of this observational retrospective study were to determine the average mortality and daily weight gain of calves and youngstock on Finnish calf rearing farms and to identify factors associated with these production parameters. National cattle register and national herd health register databases together with meat companies' databases were used to collect weight, age, breed, medication, and origin farm data for 28 228 calves transported to the 87 calf rearing farms between 1 January and 1 October 2016. A telephone questionnaire was completed by selected farms to collect management and farm-specific data. Calves were retrospectively followed for maximum 180 days since arrival to the farm. Average arrival age of the calves were 24 days (SD 14). Average calf mortality on Finnish calf rearing farms was 4.5 %. Mortality was 5.3 % on fattening farms buying milk calves, 4.6 % on specialized calf rearing farms, and 2.5 % on fattening farms buying weaned calves. Size of the calf rearing farms varied, being smallest on fattening farms for weaned calves and largest on specialized calf rearing farms. Average daily gain of the study calves was 1.074 kg/day (SD 0.166). Multilevel mixed effects logistic and linear regression models, where herd and calf batch were used as random effects, were generated to study calf level mortality and daily gain, respectively. Activities preventing transmission of pathogens between arrival batches and different age groups of animals, including application of the all in/all out principle and proper washing and disinfection of compartments for milk feeding calves between arrival batches, were associated with lower mortality and increased daily gain. In addition, higher arrival age was associated with lower mortality during the rearing period and relatively higher arrival age of the calf, compared to other calf in a same arrival batch, was associated with higher daily gain. By contrast, increased number of individual medications during the rearing period was associated with both increased mortality and decreased daily gain. There was no significant difference in mortality between farm types. Current study highlights several factors that can be affected in future to further develop the beef production chain.Peer reviewe

Sow mortality is associated with meat inspection findings

Sow meat inspection (MI) and mortality data are important sources of information for use in herd health work. This observational study examined whether MI results of sows associate with sow mortality in Finnish sow herds. We also described some MI findings of sows to create basic references in order to encourage their use in herd health work. The project was widely advertised to farmers of sow herds and practicing veterinarians. Ten herds joined the project voluntarily and 36 other herds after they were contacted by the researchers. MI data (carcass weight, lean meat percentage, arthritis, abscesses, liver condemnations, milk spots, organ condemnations, pleuritis, pneumonia, shoulder ulcers, tail biting, whole carcass condemnations, partial carcass condemnations and kg of meat condemned) were made available by the three largest slaughterhouses in Finland, and sow mortality data were obtained from the National Swine Herd Register for 39 of the study herds for the year 2014. The mean herd size of participating herds was 529 females with a standard deviation of 479 and mean annual mortality 9.0% +/- 5.2%. As much as 22.8% of the 7437 slaughtered sows had at least one MI finding. Heavy carcasses were less likely to have at least one MI finding. A median (range) of 1.8% (0-7.2) and 11.8% (0-34.6) of the sows were recorded to have a whole and partial carcass condemnation, respectively. The most common MI findings were abscesses (5.7%, 0-16.3), shoulder ulcers (3.6%, 0-22.9) and arthritis (2.1%, 0-13.3). In individual carcasses, abscesses were associated with arthritis, shoulder ulcers and pneumonia, which was indicative that these animals most likely had a systemic infection. Pneumonia findings were associated with pleuritis. At the herd level, the increase of sow mortality by 1% was associated with an increased percentage of slaughtered females with at least one MI finding 0.8% (P = 0.01). If sow mortality increased by 1%, the odds ratio for the herd having more than a median percentage of pleuritis was 1.3 (95% confidence interval; 1.01 - 1.57, P = 0.04) compared to the situation of the herd having less than a median percentage of pleuritis. Also, if sow mortality increased by 1%, the percentage of partial carcass condemnations of females increased by 0.4% (P = 0.08). These results suggest that high mortality was associated with an increase of some MI findings. MI results of sows should be used in herd health follow-up of sow health.Peer reviewe