Two faculty members of the Faculty of Mathematics and Natural Sciences at Universitas Gadjah Mada (FMIPA UGM) were officially inaugurated as professors. Dr. Abdurakhman was inaugurated as Professor of Financial Statistics, while Dr. Atok Zulijanto was inaugurated as Professor of Function Theory, Real Functions, and Baire Function Classes. The inauguration ceremony for both took place at the UGM Senate Hall on Tuesday (Nov. 18).
Delivering an inaugural speech titled “Financial Statistics: Valuation Models for Fruit Tree Lease Contracts”, Professor Abdurakhman stated that the leasing prices of fruit tree orchards in many rural areas of Indonesia generally remain simple and are based on direct agreements between owners and tenants.
For example, rental fees may be set at one million rupiah per tree for one harvest season, or even lower if more trees are leased. Such patterns reflect principles of economies of scale and distinctive social negotiation processes within agrarian communities.
In many cases, rental prices are influenced not only by the fruit’s potential yield but also by non-economic factors such as kinship, trust, and long-standing local traditions. These elements make fruit tree leasing not merely an economic agreement but also a social interaction embedded with cultural and moral values.
“Field studies conducted in several tropical fruit production centers show diverse forms of contracts and leasing agreements between orchard owners and tenants. Some contracts are fixed with prices agreed upon upfront regardless of harvest outcomes; others follow revenue-sharing schemes based on predetermined agreements, and some are combinations of both,” he said.
According to Professor Abdurakhman, this variation in contract types reflects differing perceptions of risk and uncertainty among local communities. From a financial statistics perspective, this phenomenon offers broad opportunities to explore how local communities intuitively assess risk and set return expectations, even without formal models such as Black–Scholes or modern contract theory.
“Thus, the study of fruit tree lease contracts is not only relevant for developing expectation-based valuation theories but also for building economic models grounded in social realities and local wisdom in Indonesia,” he explained.
“Based on interviews, observations, and literature reviews, at least three contract types are noteworthy for study from a financial statistics and valuation modeling perspective: the Fixed-Time Model, the Threshold-Based Dynamic Model, and the Limited-Time Dynamic Model.”
Meanwhile, Professor Atok Zulijanto, in his inaugural address titled “The Dynamics of Function Theory and Its Roles Across Disciplines”, explained that mathematical concepts such as functions (like many other mathematical ideas) originate from practical human needs.
Over time, function theory has developed into a sophisticated structure that has generated numerous new concepts, properties, and approaches, culminating in wide applications across scientific and technological fields.
“However, in its development, not all aspects of function theory or other branches of mathematics emerge out of practical necessity. Many evolve independently of immediate practical applications,” the new professor noted.
Professor Zulijanto added that mathematical theories often grow out of pure intellectual motivation, internal problem-solving, philosophical inquiry, and efforts to generalize or unify existing concepts.
Interestingly, the practical applications of such theories often become apparent only decades or even centuries after they are first formulated. Therefore, the development of mathematical theory must continue.
“This is not only to address today’s challenges but also as an intellectual investment that will serve as the foundation for future advancements in science and technology,” he stated.
Authors: Kezia and Leony
Editor: Agung Nugroho
Post-editor: Rajendra Arya
Photographer: Firsto Adi