To date, studies on the custom of mutual help that is practiced among Javanese villagers have mainly focused on the activity that can be classified under gotong royong, which is a general term referring to collective action among villagers to pooling their labor power for the construction and maintenance of public facilities. However, only a few empirical studies examine the contemporary practices of mutual help institutions in rural Java and their mechanism of adaptation. A comparative study of the arrangement of labor institution practices in lowland and upland hamlets is likely will be a worthy contribution for learning the changing labor exchange process in both research sites. The comparative study will illustrate the adaptation strategies by local people in response to changing labor conditions.

The Study was conducted in 2002, 2008, and 2009. The study in 2002 was focused on the general condition of the research sites, general and functional characteristics of labor institutions, and socio-economic structure of surveyed households. In 2008, the field research was directed to analyze the transitional process of labor institution practices in surveyed hamlets. The final study was carried out in 2009 and focused on the arrangements of hired labor for farming operations in lowland hamlets and customary selling of collective labor in upland hamlets.

By analyzing labor institutions from the perspective of the influence of particular factors such as the expansion of labor markets, resource endowments and production risk, and technological changes, it has been confirmed that these factors have massively influenced the traditional labor exchange arrangements in rural areas. In general, rural communities have developed the various innovative strategies for creating institutional labor innovations that congruent with traditional and local norms.

In lowland hamlets where the economic structure is primarily based on non-farming income and where the geographical conditions are favorable and lower production risk for farming practices, the high population mobility and the strong impact of technological changes in farming production systems have reduced the need for collective work for various farming activities.

In contrast, in upland areas where the economic structure is more dependent on farming, where there are significant geographical limitations and resource scarcity, facing higher production risk and where technological changes related to the mixed cropping system (agroforestry) have been implemented, villagers tend to demand and intensify traditional collective work arrangements such as sambatan, which, to some extent, has been supplemented by the newly introduced prayaan institution for coping with basic daily needs, including both farming and non-farming activities. However, krubutan practices still survive, despite the fact that the practices are arranged under strict rotation schedules.

Despite the transitional process that has occurred in the labor exchange institutions in rural Java, community members with tight social relationships have the capacity to adapt to the process of change. The arrangement of collective work for house construction and repair is still widely practiced. However, the division of labor and the diversification of villagers' income sources may enable well-off households to build modern houses. This possibility may reduce the need for collective work in the future because the construction and repair processes for modern houses require highly skilled labor.

In the lowland rice-growing areas of rural central Java, the practices of labor exchange for farming operations have been dramatically decreasing, and in some places, the practice has completely disappeared. Landowners could no longer rely on their own family labor or on the tradition of labor exchange. Instead, they found it convenient to hire group of laborers rather than having to deal with large numbers of individuals. The use of institutional labor innovation under various arrangements of hired labor is becoming predominant.

A significant influential factor in determining whether labor is hired for farming operations other than for harvesting and threshing is the involvement of non-farming jobs. Harvesting and threshing have been significantly influenced by three factors: the cultivation of land, the income level and the involvement of non-farming jobs. Land preparation is regarded as a task that requires skill and should be completed in a short period of time; hence, regardless of a household's socio-economic characteristics, farming households tend to hire tractor operators. For hoeing-leveling, transplanting and weeding, households whose members do not have non-farming jobs can complete these activities by fully relying on the labor of family members, whereas households whose members have permanent non-farming jobs tend to hire labor more often than households whose members have temporary non-farming jobs.

The sense of income sharing under the spirit of moral economy is, to some extent, still alive. It can be found under the bawon-bawon and bawon-operator arrangements for harvesting and threshing. Bawon-bawon has been offered only among households that cultivate small areas of land, that have high incomes and whose members have non-farming jobs. Bawon-operator has been offered by households that cultivate small areas of land, that have low incomes and whose members have non-farming jobs. For lower-income households, the high share cost of bawon-bawon practices is not affordable; hence, they prefer offering the bawon-operator system.

Even though commercialization and modernization have had a dramatic influence on hired labor arrangements, farming households still prefer to hire laborers from among their neighbors, who commonly have close social relationships, often because they are relatives. Social relationships, which commonly develop within close residential proximity, are still perceived as important by villagers involved in labor contract arrangements. The transaction and arrangement of hired labor are likely not only perceived as economic or market transactions but are also related to the social relationship system in the community. To some extent, economic rationality and moral economy coexist in hired labor arrangements for various farming operations in wet rice villages of rural Java. However, the moral economy perception among villagers has become more limited.

Villagers in less favorable mountainous areas, who face more difficulties but keenly try to search for institutional innovations, have been transforming traditional labor arrangement practices for completing various daily tasks. The practice of traditional long-established labor exchange on farming operations has been widely supplemented by a new invented institution referred to as prayaan.

Prayaan has been considerably supplementing activities that must be done in a timely manner and require many laborers and/or delicate work. These activities include terrace field construction and repair, land preparation, weeding and activities related to timber and firewood. A relatively large number of group laborers and the lower labor payments for group members are perceived as incentives and advantage by members.

The prayaan arrangement embraces not only economic or profit interest but also socio-cultural dimensions. The higher prices for non-members, the maintenance of labor charges for non-members in line with market prices, the mechanism of direct distribution of collected wages and the investment in productive assets have been among the pieces of evidence that the prayaan arrangement is a type of economic institution. However, the development of the system based on penalties that, to some degree, prevent opportunistic behavior of the members, the charging of lower labor rates if the work is hosted by members, the flexibility and priority for members in hosting laborers, and the mechanism of income disbursement for social and religious events indicate that prayaan is also oriented for social-cultural functions.

In Jati hamlet, which has access to less favorable resources, is remote, and is relatively far from the sub-central labor market (coastal region), and the survival of some traditional labor institutions has induced villagers to arrange prayaan labor primarily as an institution for earning income from either non-members or members. In Watugajah hamlet, which has access to better resources, has high people mobility, and is relatively close to the sub-central labor market, the reduction of some traditional labor institutions has induced villagers to arrange prayaan labor more as an institution for obtaining collective labor at cheaper price.

In short, the labor institution arrangements in the surveyed hamlets generally can be regarded as "independent institutions" that developed based on local collective initiatives. The development of these institutions reflects a high capacity and capability of the local people to collectively adapt various traditional labor institutions to support current basic daily needs.

In the case of labor institutions developed to complete various farming operations, these institutions can be assumed to be completely independent of formal governmental involvement. Most of these institutions have been arranged through initiatives undertaken by the local people.

Considering the effectiveness of the systems of various local institutions for supporting the daily needs of local people, there is the possibility for local government to directly become involved in or provide support to those existing institutions. Local governments must determine the proper mechanism and the type of supports in preventing the destruction of well-designed traditional systems. Well-designed and appropriate support from local governments is expected to enhance the capacity and capability of local people to strengthen economic access and to improve social and cultural life among local community members.

ジャワ農村では、農民たちがゴトン・ロヨンと呼ばれる共同労働組織を発達させていることがよく知られている。しかし、それは総称であり、さまざまな共同労働組織が、村落の中に機能ごとに重層的に存在している。本研究は、中部ジャワ農村を対象として、共同労働組織の組織形態と機能に関して分析することを課題としている。都市近郊に位置し農外労働力市場が発達した平野部稲作地域に属する2つの村落および都市部から離れて農外労働力市場が狭小な山間部畑作地域に属する2つの村落の事例を比較することを通じて、この課題への接近を試みている。

サンゴ礁隆起によって形成された山間部畑作地域は土壌が痩せており、アグロ・フォレストリーが発達している。村落内の近隣農民同士による4~5名の固定メンバー(男女別)によるグループkrubutanを作って、毎日輪番でグループ員の農作業を共同で行なっている。天水依存の畑作での作業適期を逃さないために不可欠の組織となっている。賃金支払いはなく、ホストは昼食を負担する。材木運搬や家普請など、より多くの労働力を一時に必要とする作業のために、当該農家が近隣農家に対して臨時の出役を求めるsambatanと呼ばれる共同労働組織も存在する。この場合、ホストは、食事を提供するだけで賃金支払いはない。

山間部畑作地域においてもっとも特徴的な共同労働組織はprayaanである。それは、近隣農民からなる15名程度の男女別々のグループである。グループ員は、材木運搬や段々畑作りなどのために他のメンバーに対して出役を求めることができる。そして、村落外の人物でもprayaanに対して出役を求めることができる。前者の場合、賃金は市場価格より安価であるのに対して、後者の場合、賃金は市場価格にほぼ対応している。グループ内では伝統的な共同労働組織に近似した機能を果たし、グループ外に対しては労働力の共同販売組織としての機能を果たしているといえる。後者は、農外労働力市場への接近が難しいという地理的条件を克服するための対応形態であるといえる。いずれの場合も、すべてのメンバーが出役参加の義務を負い、欠席者は罰金を支払う。年度末に、出席回数に応じて賃金が分配される。

平野部稲作地域は、灌漑施設が整備されており、稲作(二期作)と農外就業を主な所得源としている。山間部とは異なり、krubutanはすでに消滅している。農作業に関しては、sambatanも消滅している。山間部に比較して農作業が単純でかつ作業適期に余裕があるために共同労働の必要性が小さいこと、農作業に就労する農業労働者の市場が拡大していること、そして農外労働に就業している村落員が多いために出役の機会費用が高価になりつつあること、をその理由として提示することができる。ただし、家普請については、現在でも、sambatanが組織されていることが確認された。作業終了後の共食をつうじて、参加者がコミュニティーへの帰属意識を再確認する機会となっている。また、経済的に富裕な農家は、より高級な食事を提供する傾向がある。

平野部稲作地域では、以前から、一部の農作業において賃金労働者を雇用することが一般的であった。しかし、1980年代末以降の技術革新にともなって、雇用の形態に変化が見られる。以前は水牛を用いて自家労働力で行なっていた耕起は、耕耘機オペレーターへの委託に変わった。田植の場合、近隣農民同士ガ労働交換を行なっていたのに対して、近年は村落外の田植グループに作業委託することが一般的になっている。収穫・調整の場合、村落農民が誰でも参加でき出来高に応じて報酬を得られた慣習(bawon)に代わって、外部の商人などが労働者を組織して作業を受託するtebasanが普及している。農外労働で多忙な農家が取引費用を節約しようとした結果であると解釈できる。ただし、bawonの場合、低所得層が雇用される傾向があり、村落内での所得再分配機能を果たしていることが窺える。

以上の分析から、中部ジャワ農村において慣習的な共同労働組織が大きく変化しつつあること、その変化の背景に農外労働力市場の拡大があることが確認できた。ただし、農外労働力市場の拡大の趨勢とともに共同労働組織が弱体化するというリニアーな関係が必ずしも成立しているわけではない点が重要である。すなわち、山間部畑作地域のprayaanに見られるように、共同労働組織を強化することによって農外労働力市場の展開に対応しようとする動きが見られるのである。また、農外労働力市場が拡大した平野部稲作地域においても、コミュニティー内の人間関係に配慮しつつ労働組織が形成されていることが確認される。

以上、本研究においては、4つの集落を対象としたフィールド・ワークを通じて、中部ジャワ農村における共同労働組織の組織形態と機能に関する分析を行なった。この分析成果は、学術上、応用上資するところが少なくない。よって審査委員一同は、本論文が博士(農学)の学位論文として価値あるものと認めた。