Probit Model Research Articles

Persistence of the armed conflict in Colombia: an agreement without peace

PurposeThe aim is to analyze the armed conflict persistence in Colombia from 2008 to 2018 based on the financial viability hypothesis (rebellion occurs when war net revenue is nonnegative).Design/methodology/approachThe methodology is quantitative. Firstly, a nonparametric Kaplan–Meier functions and survival risk functions are developed as initial approximation. Subsequently, a Probit model with panel data is implemented and the covariates are grouped into three dimensions: opportunity, grievance and institutional-political.FindingsThe viability hypothesis boosts the continuity of the armed conflict, which is enhanced and perpetuated by the viability and financial incentives from public revenues and natural resources, while the grievance, political fragmentation and institutional dimensions contribute to the opportunity structure in Collier that makes the conflict militarily and economically viable.Research limitations/implicationsLack of information for some states in Colombia prevents a much more holistic analysis.Practical implicationsPostulate what is required by the Colombian State to cut off the sources of financing of armed groups and thus, one of the determinants of the continuity of the conflict.Social implicationsThe political fragmentation contributes to rebellion, and that variables representing the dimensions of grievance and institutional presence contribute to the opportunity structure that makes the conflict in Colombia militarily and economically viable.Originality/valueThis research proposes as a novelty to incorporate the viability hypothesis with some factors related to the grievance that explain the persistence of the armed conflict as a consequence of decreasing recruitment costs for the insurgent groups, a situation that contributes to the opportunity structure and financial viability of the conflict.

Assessing technical efficiency and farmer adoption of organic rice in the Red River Delta of Vietnam: An application of metafrontier DEA and Probit Models

Assessing technical efficiency and farmer adoption of organic rice in the Red River Delta of Vietnam: An application of metafrontier DEA and Probit Models

Decisions to Adapt Family Farms to Climate Change in Cameroon

ABSTRACTThe goal of this research is to identify the factors that explain family farm adaptation to climate change, as well as the complementarity between these various adaptation strategies. A multivariate probit model was used to analyse secondary data from 721 family farms. According to statistical analysis, 72% of farmers correctly perceive temperature increases over time and variations in rainfall as daily realities that must be incorporated into their farming practices. The most concerning phenomena are drought (52%), and flooding (34%). Econometric analysis reveals that the adaptation decision is explained by the farmer's experience, household size, farm size, religion, agroecological zone, producer cooperation, and credit facilities. Specifically, farm size had a positive and statistically significant effect on the likelihood of irrigating fields by 12.2% and using short‐duration seeds by 26.9%. Furthermore, there was a strong correlation between the different coping strategies, confirming the complementarity hypothesis. These findings imply that strengthening agricultural research and extension services, including farmer access to information, education, and training, is critical to the development of an effective climate change adaptation process.

Examining effects of climate information utilization by climate-vulnerability groups in the northern region of Ghana

Impacts of climate change on climate-vulnerable populations receive little attention in the literature compared to the general population across the globe, including Ghana’s Northern Region, than it has on the availability, sources, and kinds of climate services. Understanding the level of effects of utilizing climate information on farmers’ livelihoods is important for climate policy evaluation. Therefore, this study investigates how farmers in three climate-vulnerable groups in Ghana’s Northern Region make adaptation decisions based on climate information. Using a concurrent nested mixed research (quantitative and qualitative) approach, we collected data from 384 sampled farm household respondents, focus group discussions, and experts’ (Key-informants) opinions on climate change in the region. We analyze the data using descriptive statistics and a probit model. The results of mean statistics indicate that whereas farmers across climate-vulnerability groups perceived climate change and variability, the less climate-vulnerable group utilized more climate information for adaptation 7.1 than their counterparts, 5.2 and 3.3 for moderate to high vulnerability, respectively. Also, the probit model result reveals that farmers in the three climate-vulnerable groups are negatively associated with utilizing climate information in their adoption of adaptation strategies for floods and droughts, but they are positively and significantly influenced by climate information in their decision to implement early planting and pest/disease control. Furthermore, although the results show that using climate information boosts farmers’ chances of getting credit by 102.5%, there is no significant chance that farmers would be able to get credit without climate information. The study concludes that, to a greater extent, climate information significantly influences farmers’ decisions regarding adaptation strategies in the region.

Physical, mental, and financial wellbeing in urban Pakistan: linkages and empirical evidence

ABSTRACT There has been vast research on the link between mental health and financial wellbeing but less emphasis has been on its connection with physical health. This paper aims to estimate the effect of past mental health and present physical health on present financial wellbeing in a mediation analysis. The data was collected for the year 2022 in urban Pakistan through questionnaire method from the head (the financial decision maker or the bread winner) of the sample households. The total sample size of 400 households was selected using Yamane’s formula. Using proportional stratified random sampling technique, the sample was allocated proportionally among all the provinces and the corresponding sampled cities. The results from the ordered probit regression analyses suggest that the present physical health partially mediates the relationship between past mental health and present financial wellbeing in terms of magnitude. Moreover, the financial wellbeing is positively associated with past mental health and present physical health of the sample households. The Government is advised to put more emphasis on mental health awareness sessions via social media and other channels as mental health has positive influence on physical health which in turn has positive effect on financial wellbeing.

Understanding the Nexus of Extension Teaching Methods and Adoption of Improved Agricultural Production Technologies: Empirical Evidence from Cowpea Farmers in Kogi State, Nigeria

This study assessed the nexus of extension teaching methods and the adoption of improved production technologies. A three-staged sampling technique was adopted in selecting two hundred (200) cowpea farmers. Primary data obtained using the Kobocollect toolbox was analyzed with adoption score/index and ordered probit regression model. Findings from this study showed that 79 % of the respondents were males while 21 % were females. The mean age among cowpea farmers was 49 years. Furthermore, 90.5 % of the respondents adopted the recommended seed rate, 87 % adopted the recommended planting date, and 84.5 % adopted the recommended weeding time. Most (20.5 %) of the respondents had an adoption score and index of 8 and 0.57; while 1.5 % of the cowpea farmers recorded an adoption score and adoption index of 10 and 0.7. Also, 45 % of the cowpea farmers were in the low adoption category, and 27.5 % of each of the sampled cowpea farmers were found in the medium and high adoption category. Individual extension teaching method (β = 1.192), mass extension teaching method (β = -0.189), a combination of individual, group and mass extension teaching methods (β = 0.044), gender (β = -0.124), farming experience (β = -0.019), and income (β = -0.00000276) significantly influenced the extent of adoption of recommended cowpea production practices. The study concluded that individual, and a combination of individual, mass and group extension teaching methods have positive effects on the extent of adoption of recommended cowpea production practices. Amongst others, the study recommended the use of these teaching methods by both private and public extension agents in disseminating information on improved farming practices.

Seed longevity: analysing post-storage germination data in R to fit the viability equation

Abstract For many decades, seed germination data have been modelled by probit analysis. In particular, it is the basis of the seed viability equation used, in the first instance, to describe the decline in germination of seeds in storage, but then also the rate of the decline, depending on seed moisture content and the temperature of storage. The underlying assumption of a probit model is that the response follows a normal distribution, in this case, loss of the ability to germinate over time. Probit analysis also takes into account the binomial error associated with germination data. Many statistical packages have probit analysis as an option within the generalized linear modelling framework; here, we present code for applying probit analysis in the free software, R. Codes are provided for fitting a single survival curve, for a single seed lot stored in a constant storage environment; for fitting multiple survival curves and evaluating the effect of constraining parameters for the different seed lots; and lastly, to model the moisture relations of seed longevity. The code bases provided could also be used in pollen and fern/bryophyte spore longevity modelling.

Comparative effective dose of ciprofol and propofol in suppressing cardiovascular responses to tracheal intubation

Ciprofol, a novel γ-aminobutyric acid receptor agonist, outperforms propofol with minimal cardiovascular effects, higher potency, reduced injection pain, and a broader safety margin. Despite these advantages, ciprofol’s clinical research is still emerging. This study compares the median effective dose (ED50) and adverse reactions of ciprofol and propofol, in conjunction with sufentanil, for suppressing cardiovascular responses during tracheal intubation. Fifty-three adult patients scheduled for tracheal intubation under general anesthesia were enrolled and randomly assigned to receive either ciprofol (Group C) or propofol (Group P), according to a random number table. Tracheal intubation was performed using a standardized laryngoscope and endotracheal tube. The Dixon’s up-and-down method was employed to determine the ED50 and 95% effective dose (ED95) of ciprofol and propofol in inhibiting cardiovascular responses during tracheal intubation. Based on the pilot study, the initial dose for ciprofol was set at 0.35 mg/kg (with a 0.01 mg/kg increment) and for propofol at 2.0 mg/kg (with a 0.1 mg/kg increment). Probit analysis was applied to derive dose-response curves, while adverse reactions were continuously monitored. A total of 54 participants were included, with 24 in group C (1 excluded) and 30 in group P. Probit analysis revealed that the ED50 of ciprofol for inhibiting cardiovascular responses to tracheal intubation were 0.326 mg/kg (95% CI 0.304–0.337 mg/kg), and for propofol, 1.541 mg/kg (95% CI 1.481–1.599 mg/kg). The heart rate in group P was significantly higher than the group C at 1 minute (p = 0.026) and 3 minutes (p = 0.016) post-intubation. Systolic and diastolic blood pressures (SBP and DBP) decreased significantly before and after intubation compared to baseline values in both groups (p< 0.05). Group C experienced significantly less injection pain (p = 0.001), although the incidence of other adverse effects was not statistically different between groups (p > 0.05).Clinical Trial Registration: hppts://ClinicalTrials.gov; Identifier: NCT06095570(18/10/2023).

Economic Freedom and Presidential Elections: A Bayesian Spatial Probit Hierarchical Modeling Approach

ABSTRACTThere is a growing consensus that spatial effects can help to explain electoral outcomes. Additionally, the concept of economic freedom is also correlated with many different economic outcomes. This paper combines these two ideas using a Bayesian hierarchical spatial probit econometric model. Hierarchical models have a long history in the Bayesian literature and allow for the estimation of Level 1 (county) and Level 2 (state) variables. In this study, we use county‐level data on county‐level votes for Donald Trump in the 2020 presidential election and control for state‐level economic freedom using a newly developed Bayesian hierarchical spatial probit model. The results indicate that state‐level economic freedom contributed positively to Donald Trump's vote at the county level.

Institutional services towards climate action: A case of climate change adaptation of agro-pastoralists in the drylands of Nigeria

ABSTRACT The agro-pastoral sector is highly vulnerable to climate change. Animal growth and milk production are affected by a reduced availability and quality of fodder and forage. Water shortages for livestock also pose a significant threat to the sector’s sustainability. To adapt, farmers depend on supportive environments that recognise the crucial role of institutional services in promoting climate action. This study analysed the effect of access to institutional services on climate change adaptation strategies of agro-pastoralists in the dry zone of Nigeria. Data were collected using a structured questionnaire to elicit information from 360 agro-pastoralist farmers, and a multivariate probit regression model was used for the analysis. The results revealed that crop residue-hay conservation, irrigation, and destocking adaptations were positively influenced by extension services, climate change, and livestock-related information. Destocking is negatively influenced by access to credit, climate change, and livestock-related information. Dissemination of climate change information, provision of credit, and construction of water-efficient irrigation facilities are essential to support agro-pastoralists in adapting to climate challenges. Appropriate institutional services from governmental and non-governmental actors through site-specific support and the creation of an enabling environment will enable agro-pastoralists to adopt water-efficient irrigation and improved pasture preservation practices that will make the sector more resilient to the changing environment.

Market integration and resident health in China

This paper uses data from the China Health and Nutrition Survey (CHNS) to study the impact of market integration on residents’ health. The empirical results based on the probit model show that market integration has a significant dampening effect on resident incidence. For every one-unit increase in the degree of market integration, the probability of residents becoming sick decreases by approximately 1.45%. Moreover, after a series of robustness tests, the conclusion is still valid. This study further analyses the potential mechanism and finds that the promotion of market integration can improve the medical conditions available to residents, optimize the nutritional indices of residents, and reduce labor load of residents, thus improving their health. The results of the heterogeneity test show that there are certain differences in the impact of market integration on the health level of residents of different genders, ages and income classes. At the same time, this study also verifies that there is a synergistic effect between internet penetration and market integration.

Natural resource dependence and war nexus: new insights

ABSTRACT This paper examines the channels through which resource dependence affects the probability of war. We consider all types of war within a worldwide panel dataset of all countries and territories, spanning the period 1960-2022. We systematically estimate the probability of war using a set of economic and geographic characteristics, including democracy, demography, legal origin, militarism, and sectoral composition. Using a panel probit model, we find that natural resources rents, military expenditures, and the presence of a common law tradition significantly increase the probability of war occurrence. However, we notice that this probability is decreasing in the level of economic development and democratization, and with the size of the services sector and trade openness. We also find that the effect of resource dependence varies by level of economic development, continent, landlocked status, legal origin, colonial history, and war type with civil wars being the salient type. Overall, we provide novel and updated evidence on an important dimension of the vexing question of the so-called ‘resource curse’.

Interest in Sports and Sports Betting

There has been a worldwide growth in sports betting activity, in part due to the widespread use of the Internet. The objective of this research is to make a joint analysis of the probabilities of offline and online sports gambling participation, focusing on their association with sport-related variables. To this aim, we estimate a bivariate probit model of online and offline sports betting using the 2022 Spanish Survey of Sporting Habits, a cross-sectional database representative of the Spanish population (sample size: 10,267 observations). In general, interest in sports and sports practice are correlated with sports betting. Moreover, people who play sports and, in particular, those who play football, have a higher probability of betting offline. In the case of online betting, all sport-related variables are statistically significant but sports participation. Another noteworthy result is the positive correlation in the random terms of the probabilities of offline and online sports betting.

Changing patterns of general practice services during a period of public sector investment in Britain.

Given the importance of GP care to the public's health, it is important that we understand how patterns of service use change as levels of investment change. This study investigated GP use in Britain in conjunction with use of outpatient services during a period of investment and during a period of austerity. The study used data from the British Household Panel Survey (BHPS) that included service use, morbidity (as an indicator of need) and socio-demographic characteristics (e.g., employment, age, education, and sex). Data for 2000, 2004, and 2008, were specifically chosen for comparison with data from 2015, 2016 and 2017. Service use and respondent characteristics were described using measures of central tendency and dispersion. Multivariable analyses were undertaken using recursive bivariate probit (RBVP) and probit analyses separately for each study year. All analyses were adjusted for cross-sectional weighting. BHPS respondents who used outpatient services or GP services had higher morbidity compared to survey participants who did not. Older people, people with lower educational attainment and employed people had higher mean morbidity indices in each study year as did females. Morbidity among service users tended to decline slightly over time. RBVP analyses revealed a significant positive correlation in residuals between outpatient and GP functions in 2000 and 2004 but not 2008. GP consultations and outpatient use remained largely unrelated to socio-economic factors in each year. Survey participants who reported hearing or vision impairment conditions were consistently less likely to use GP or outpatient services in 2000 and 2004, in 2008. The results are broadly indicative of stable relationships in service use during a period of healthcare investment but change during austerity. Those who reported, vision, hearing, and skin conditions were consistently less likely to report use of GP or outpatient services, controlling for other aspects of health.

Natural Shocks and Internal Labor Migration: Evidence from Pakistan

Pakistan is among the hardest hit countries by natural disasters, particularly floods, earthquakes, and droughts. The study examines the impact of floods, earthquakes, and droughts on Pakistan's internal labor migration. Using the probit model, we determine whether the labor migration decision will differ in shock-affected and other districts in Pakistan. The findings show that internal labor migration likely decreases in shock-affected districts compared to other districts. We analyze the data separately for the rural and urban, male and female, and employed, unemployed and not-in-labor force for the robustness check. Urban region evidence is consistent with baseline results. However, for rural regions, the coefficient of natural shocks is statistically insignificant in the whole sample and across subsamples meaning that natural shocks have no significant impact on internal labor migration in the rural region.

Factors Affecting Compliance of Fringe Benefit Tax among Private Sector Companies in Malawi

Tax revenue is the major source of public resources and tax compliance is vital for any government to have adequate financial resources for implementing development projects and provision of social services to its citizens. Effective strategies for enhancing tax compliance are those informed by research. One of the taxes that companies pay is Fringe Benefit Tax (FBT). This study investigated determinants of FBT compliance among private sector companies in Malawi, grounded in the Expected Utility Theory. The study employed a multistage cluster sampling technique through which 128 registered private sector companies out of 1133 were surveyed. The surveyed companies were those that are located in Malawi’s three major cities of Blantyre, Lilongwe and Mzuzu, where corporate concentration is highest. Data analysis was conducted in STATA by applying a Probit model to identify factors influencing FBT compliance. The findings indicate that firm size, method of tax remittance and trust of good usage significantly affect compliance. The study recommended that MRA should enhance promotion of electronic platforms for paying taxes and consider developing a special FBT package that could be more convenient to small companies. The government should work hard towards gaining more trust from taxpayers through improvements on accountability and transparency in the way public finances are spent. With the existence of Access to Information Act, it should be easy for the public to access information on government spending there by increasing trust and tax compliance.

Effect of Dexmedetomidine on the ED50 and ED95 of Sufentanil in Patient-Controlled Intravenous Analgesia After Cesarean Section: A Randomized, Controlled, Double-Blind Trial.

To determine the effect of dexmedetomidine on the ED50 and ED95 of sufentanil in patient-controlled intravenous analgesia (PCIA) after cesarean section. Parturients who underwent elective cesarean section (n = 80) were randomly assigned to either the sufentanil group (S group) or the dexmedetomidine-sufentanil combination group (DS group). Patients in the S group received a combination of sufentanil, 5 mg of tropisetron, and saline, whereas patients in the DS group were administered 1.5µg/kg of dexmedetomidine in addition to sufentanil, 5 mg of tropisetron, and saline. The ED50 and ED95 of sufentanil were determined by Dixon sequential method. We used probit regression to calculate the ED50, ED95, and 95% confidence intervals for sufentanil in each group. The ED50 and ED95 for sufentanil in the S group were 1.634 (95% CI: 1.476-1.810)µg/kg and 2.035 (95% CI: 1.841-3.312)µg/kg, respectively. The ED50 and ED95 for sufentanil in the DS group were 1.275 (95% CI: 1.187-1.353)µg/kg and 1.503 (95% CI: 1.406-1.824)µg/kg. The VAS scores with rest at t5 and with movement at t4- t5 were lower in the DS group (P< 0.05). The t2-t5 Ramsay scores in the DS group were higher than those in the S group (P< 0.05). The doses of sufentanil and tramadol were markedly reduced in the DS group, while the onset of first lactation occurred significantly earlier in the DS group (P< 0.05). Compared with the S group, the DS group had a lower incidence of nausea, vomiting, and skin itching (P< 0.05), and lower frequency of patient-controlled analgesia (PCA) episodes (P< 0.05), and better postoperative pain satisfaction (P< 0.05). The 1.5µg/kg dexmedetomidine can significantly decrease the ED50 and ED95 of sufentanil in patient-controlled intravenous analgesia after cesarean section, provide good postoperative analgesia and sedation, and promote the earlier occurrence of first lactation.

Sequence and Chronology of Permanent Teeth Eruption in 5-18-Year-Old School Children of Chennai and the Influence of Sex, BMI, and Socio-Economic Status.

This study aimed to determine the sequence and eruption chronology of permanent teeth in school children and adolescents of Chennai and compare the findings with an existing standard table. Additionally, the study also attempted to explore the influence of sex, body mass index (BMI), and socioeconomic status (SES) on tooth eruption patterns. A cross-sectional study was designed, and 12,650 children aged 5-18 years were selected from thirty-five schools using a multistage random sampling method. The clinical eruption status of all permanent teeth was evaluated using a new grading system. The chronology of permanent teeth eruption was determined using probit regression analysis while the intergroup comparison was carried out using the unpaired t-test and anova test. The study sample included 6414 males and 6236 females. The mandibular first molar emerged as the first tooth at 5.5 years, whereas the maxillary second molar was the last to erupt, appearing at 11.9 years. A statistically significant difference (p < 0.0001) was noted between the sexes, BMI, and SES categories for most teeth; however, the variation was only 1-3 months. An accelerated eruption pattern was observed for all teeth, except the mandibular canines, with a notable reversal in the maxillary sequence, where canines erupted before the first premolars. Tooth eruption occurred earlier in females, in the lower jaw, right side, in normal BMI, and high SES categories. A new eruption chart has been proposed for the Indian population, based on robust data from this study, providing an updated standard reference for assessing permanent tooth emergence.

Các nhân tố ảnh hưởng tới rào cản năng lượng của các doanh nghiệp Việt Nam

This study analyzes the factors impacting energy constraints (EC) that Vietnamese enterprises face, based on World Bank survey data from businesses during the 2009 2023 period. Using a probit regression model, the study examines factors such as firm size, firm age, industry type, ownership structure, financial and institutional constraints, along with power outage occurrences, to identify their relationship with EC. The results show that firm size, manufacturing industry, product innovation, and financial and institutional barriers significantly impact energy constraints. Large enterprises, manufacturing firms, and those engaged in product innovation experience more energy-related challenges due to high energy demands and dependency on stable energy supply. Further analysis reveals differences between small and medium enterprises and large enterprises, as well as between energy-intensive and less energy-intensive industries. Meanwhile, firm age and ownership structure show no clear influence on energy constraints. Notably, financial and institutional barriers are key factors that increase energy constraints, hindering enterprises’ ability to invest in alternative energy solutions.

Performance Validation and Blood Donation Analysis in Nagqu, Tibet, One of the Highest Cities in the World.

Due to the unique geographical and climatic conditions in Nagqu (Tibet), the blood station laboratory was only fully established and accredited by 2020. This study validated the performance of the laboratory's blood screening system and analyzed recent trends in blood donation and screening effectiveness. Various serum samples were used to assess the performance of hepatitis B, hepatitis C, HIV, and syphilis tests, both serological and nucleic acid tests. Donation data were also collected and analyzed. Serological testing demonstrated excellent sensitivity, specificity, and reproducibility (all 100%), with detection limits for HBsAg, HCV Ab, HIV-1 Ab, HIV-1 p24, and TP Ab of 0.2 IU/mL, 0.013 NCU/mL, 0.25 NCU/mL, 1.25 U/mL, and 1.5 mIU/mL, respectively. Nucleic acid testing systems also achieved 100% reproducibility with precision below 5%. PROBIT analysis revealed the 95% detection limits for HBV DNA, HCV RNA, and HIV-1 RNA as 8.29, 97.14, and 40.52 IU/mL, respectively. The study also found a high rate of unqualified donations for local markers such as ALT, HBsAg, syphilis, and HBV DNA. The validation confirmed the screening system's high sensitivity, specificity, and reproducibility, highlighting the importance of effective predonation checks to ensure a safe blood supply in high-altitude areas.