台灣農家人力資本與時間配置之分析

Analysis of Human Capital and Time Allocation of Farm Households in Taiwan

台灣在過去二十年來正面臨農業工作人口萎縮及高度老化的問題，農業就業人數由1978年的近160萬人，縮減至2012年的54萬人，而65歲以上的農業就業人數，則從1993年的6.6%增加至2012年的17.1%。然而農家戶數僅小幅下降，由1990年的86萬戶減少至2011年的78萬戶，同時期農家人口數則由1990年的429萬人下降至2011的294萬人，雖然人數減少約三成，但仍有近3百萬人，人口數下降幅度比農戶數大。本文嘗試利用2010年農林漁牧普查資料，探討農家成員在農場內及農場外工作時間的配置情形，以了解農家從業人員青壯人口流失而導致老化的原因。本文藉由建構異質性人力資本的農家時間配置模型，並以multinomial logit模型估計農家成員的時間配置選擇。我們的實證結果發現農家成員於農場內及農場外工作的時間配置呈現二元化的現象，亦即農家成員若教育程度較高者大多從事農場外工作，而教育程度較低者則從事農場內的工作。我們進一步以農業收入函數估計農業生產之教育報酬，並估計農家成員從事農場外工作之教育報酬，結果發現農場內工作的教育報酬遠低於農場外教育報酬。此可解釋隨著農家下一代教育程度的提升，使得農家新一代青壯人口選擇轉移至報酬較高的非農業部門工作，而老一代仍持續於農場工作，進而產生農家成員間時間配置近四二元分流的現象。另外，農場規模大小亦為影響農家成員時間配置的重要因素之一，藉由經營規模的擴張將可以增加農家成員於農場內的工作日數及降低其於農場外工作的機率。

Taiwan has experienced a rapidly shrinking and aging agricultural workforce in past two decades. The workforce employed in agriculture has dropped from 160 thousand in 1978 to 54 thousand in 2012. And, the proportion of farm workers aged more than 65 has nearly tripled from 6.6% in 1993 to 17.1% in 2012. However, the number of farm households has only declined slightly from 860 thousand in 1990 to 780 thousand in 2011 and during the same period the number of farm household members has only declined from 4.3 million to 3 million. Thus, understanding the farm households' stock of human capital and their behavior of time allocation becomes the first step to overcome the crisis of a disappearing agricultural sector. In this paper, we use the 2010 Census of Agricultural, Forestry, Fishery, and Husbandry (AFHH) to analyze the time allocation decision of farm household members. We develop a simple farm household model with heterogeneous skilled labor inputs and apply a multinomial logit model to estimate the time allocation of farm household members. The empirical results show that there is a mechanism of self-selection according to the level of human capital within farm households. A dichotomous time allocation is observed, that is educated workers allocated most of their time on off-farm work, while less educated workers allocated their time on farm work. The wage differential between skilled and less skilled workers from off-farm work is much higher than the difference in marginal return from farm production. The relative high return of skilled workers from the offfarm work may be the major reason of the dichotomous time allocation between educated and less educated workers. In addition, the farm size is an important factor that affects the time allocation. An expansion in the cultivated land will increase the days of work on farm and reduce the probability of off-farm employment.