The results of the maximum likelihood estimator of the Cobb-Douglas stochastic production frontier and technical inefficiency effect model for different organic vegetable farmers groups are presented in Table 1. In the stochastic production frontier model, the farmer’s frontier production is the dependent variable. Maximum likelihood techniques are used to estimate the production function parameters b. In Section 2, the technical inefficiency (MU) is the dependent variable and the normal distribution is used to estimate the technical inefficiency parameters z, using b computed.
The first model, examining total organic vegetable farmers, labor, land and organic manure, shows these variables have a significant positive relationship with frontier output at the 1% level. This aligns with studies by
Songsrirote and Singhapreecha (2007) and
Issaka et al., (2016). Capital is not significant in this model. Organic manure significantly impacts technical efficiency, with a one-unit increase leading to a 0.4693 unit increase in frontier production (
Palathingal, 2019).
Shinde and Hunje (2019) also found organic manure improved seed quality. The constant is significant in this model. In the technical inefficiency model, age and experience are significant at 5%, while education is not. The positive coefficient for age suggests inefficiency increases with age, aligning with
Tzouvelekas et al., (2001). The negative coefficient for experience indicates more experienced farmers are more efficient, corroborating
Lohr and Park (2006) and
Nwaru and Ndukwu (2012).
Farmers are divided into two groups based on land size: more than two acres and less than two acres. Both groups show significance at 1%. For large-scale farmers, organic manure and land are significant at 10% and 1%, respectively. For small-scale farmers, all variables are significant at 1%, with capital having the greatest impact. Technical inefficiency variables age and experience are significant for large-scale farmers, with age positively related to inefficiency and experience negatively, the results align with the findings of
Nastis et al., (2012). For small-scale farmers, no inefficiency variables are significant. The study also categorized farmers by occupation: full-time (196) and part-time (104). Both models show significance at 1%.
For full-time farmers, land, organic manure and labor are significant at 1%, while capital is not. For part-time farmers, organic manure and capital are important at 1% and 10%, respectively. In the technical inefficiency model, education is key for full-time farmers, reducing inefficiency by 0.0513 units per year of schooling. Age and experience are not significant for full-time farmers. For part-time farmers, only age is significant at 5% and positively affects technical efficiency.
Being a member of a farming group can provide farmers with access to information about innovative techniques, policies and subsidies. Both models are statistically significant at the 1% level. The study reveals that land, labor and organic manure are statistically significant at 1% for both groups, while capital is only significant for farmers in a farming group. Capital contributes significantly to the frontier production of group members, while organic manure impacts frontier production of non-members. In the technical inefficiency model, experience is significant at 5% in the member group model, indicating a positive relationship with technical efficiency. No other variables are significant in the non-member group. A study of (
Parvathi and Waibel, 2016) found that joint farming has a significant impact on income from organic farming compared to conventional black pepper farming. After determining the appropriate model, the average technical efficiency for each group and individual farmer was calculated. The distribution of individual technical efficiency of organic vegetable farmers is summarized in the table. The estimated mean technical efficiency is 21.4%, indicating significant inefficiencies in production and potential for improvement. To achieve full efficiency, farmers need to increase output by 78.6%. The highest technical efficiency observed is 82.78%, indicating an inefficiency of 17.22%. The least efficient farmer requires a 78.6% improvement. Approximately half of the farmers (57.7%) are highly inefficient, utilizing less than 50% of their total capacity. Most farmers are not optimizing their resource use to achieve full efficiency.
Table 2 presents the distribution of farmers according to their technical efficiency indices. This distribution facilitates a comparative analysis of the technical efficiency levels among different groups of farmers. Furthermore, it provides insights into whether specific group characteristics have a significant influence on their technical efficiency. The comparison based on farm size shows little difference in technical efficiency between large-scale (28.46%) and small-scale (28.78%) farmers, with both groups being highly inefficient. Large-scale farmers can improve output by 71.54% and small-scale farmers by 72.22%, to reach full efficiency. This finding contradicts the results of
Rajendran et al., (2015), who reported that larger farms tend to be more efficient. Similarly, a study by
Ngo et al., (2025) found a positive correlation between farm size and technical efficiency. However, the current study did not support these conclusions. Instead, the findings align with Sharma,
Dutta and Singh (2024), who reported a neutral relationship between land size and productivity. Overall, both farm sizes exhibit significant potential for efficiency improvement.
Comparisons based on occupation reveal that full-time farmers (23.35% efficiency) and part-time farmers (23.19% efficiency) have similar levels of technical efficiency. Both groups are highly inefficient, needing improvements of 76.65% and 76.81%, respectively, to achieve full efficiency. This suggests that part-time farmers can match the efficiency of full-time farmers despite their divided focus. Both groups have substantial room for efficiency enhancement.
Membership in farming groups provides a slight efficiency advantage, with members having a mean efficiency of 28.18% compared to 22.82% for non-members. However, 82.9% of group members and 92.5% of non-members are below 50% efficiency. Both groups are highly inefficient, requiring improvements of 71.82% and 77.18%, respectively, to reach full efficiency. Despite the small efficiency gain, both member and non-member farmers have significant potential for improvement. Table 2 depicts the cumulative technical efficiency distributions obtained the normal stochastic frontier model.
The study compares technical efficiency across seven farmer categories, revealing key findings. Land, labour, capital and organic manure positively impact frontier production in small-scale farmers, males and farm group members. Organic manure significantly boosts output in all models except small-scale, full-time and group members. Land is significant except for farmers with other jobs, while labor and capital are insignificant in large-scale and other job models, negatively impacting large-scale farmers. Education reduces inefficiency in full-time farmers and age increases inefficiency in total, large-scale, male and other job models. Experience decreases in inefficiency in all the farmer’s groups. Membership, land size and occupation show minimal impact on overall efficiency. Overall, significant inefficiencies exist across all farmer groups, highlighting the need for targeted interventions to enhance technical efficiency.