ÖZETBu, araştırmada, Türkiye ve özelliHe Kuzeydoğu Anadolutarımlarının bitkisel üretim kesimlerini temsilen ele almanmuhtelif ürünlerin verim, fiyat ve gayrisafi hasıla1amufu yıldanyıla görülen şiddetli dalgala:nmalardan ileri gelen belirsiz·lik ve bu belirsizliğin iktisadi tesirleri incelenmektedir,.Elde edilen bulgulardan, gerek Türkiye ve gerekse KuzeydoğuAnadolu düzeyinde yetiştirilen belli başlı ürünlerinverim, fiyat vıe dolayısiyle gayri safı hasılalarının yıldan yılaşiddetli dalgalanmalar gösterdiği anlaşılmaktadır. Bu ise,çiftçiyi önemli bir teknik ve ekonomik beMrsizlikle karşı karşıyabırakmaktadır. Bu durumun bir sonucu olarak; tarım·~al üretimin rasyonel bir şekilde planlanması güçleşmekte,kaynaklar etkin olmıyan bileşim 'Ve miktarlarda kullanılmakta,işgücü sermaye yerine ikame ediımek~e ve uzun vadeli yatırımlardan kaçımlmaktadır.SUMMARY: UNCERTAINTY AND ITS ECONOMIC EFFECTSON THE AGRICULTURE OF TURKEY AND NORTH EAST REGIONDecision-making withDut completeknowledge is a problem ofmajor significance in the _agriculturaleconomy. Because of lincertainty,productian planning isfrequently imperfect. This resultsin lowt:r incomes for farm peopleand a mis-alloca~ion of produe.üveresources.This study estimates thedegree of variabi1ity in yields,prices and gross incomes associatedwith varioliS types of crop pm·duction in Turkeyand specificallyin the Northeastern Region andinvestigates the relationships betweenstability and level of farmincome from particular croppingsystems. Knowledge of these relationshipsis prerequisite to rationalchoices among crops or combinationsof crops to .produce.For example, farmers must decidewhether to pioduce: a) high incomecrops with a correspondinglyhigh risk of large losses, b)lower risk crops with tower aver-22'age iDeome, c) a combination ofhigh and low risk crops.In line with these ge;1eralgoals: the specific objectives ofthis studyare: 1) to estimateabsolute and relative variabilityof product priees, yields, andgross income of major crops, 2)to compare various 'erop diversi·fication systems from the stand.point of variability and level ofincome in the Northeastern Region,3) to investigate the effectsof uncertainty upon allacativeefficiency in agriculture.Variability measures of indi·vidual crops were derived exdusivelyfromthe yield and prkeseries compiIed by the State hıstituteof Statics and the gross incomecomputed here as unit prkeX yield per hectare for the periodof 1948·1970 for Turkeyand 19511970for the Northeastern ~egion.Variability, in erop produetionstems form the fact thateornputed associated with theindividual farrner's view of un.predictable or «randam» variation.In the first, it is assamed thatin the eyes of the farmer any deviationfrom the long-rurn. mean isa randam or unpredictable eventand the original series used tocompute the «coefficient of variation'}by the fol1owing equation:yields, priees and ineames areinflueneed by many variables inan unpredictable or «randam»manner, From the standpoint ofthe individual farmer, what portionof the total variation in yieldpriee and income is unpredietableor «random» aııd what portianpredietable? In this study, twotypes of variabiIity measures areCoeffident of variation----- ...; variance1948-70 or 1951-70 meanX 100eaeh series and then deviationsfrom this trend line is used toeompute the «eoefficient of randomvariation» by the fol1owingequation:In the second, it is assumed thatfarmers reeognize certain longmnphysİcal and eeonomie trendsand view the «randoID,) elementas a deviatimı from these trends.Thus, a trend Line is fitted to. . ... Standard deviation of regressionCoeffıcıent o randoın yanatıon ='1948-70 or 1951-70 mean X 100The results obtained on theoasis of the variability measures,cpmputed as described ab'ove, aresuınmarized in Table ı. Thus :A - Yield uncertainty: Accardingto the coeffieients of variationand random variation, thereis a great deal of uneertainty inyields of principal crops of bothTurkeyand the speeifıc region ofNortheast, The ranking eorrespondsc10sely with eommon kn-owledgecemeerning relative yieldvariabiIity of crops. ,Yield variabilityof irrigated crops usual1y isless than for dryland farmedcrops.B -- Priee uncertainty: Coefficientsof variation on priees arealso' high in almost all crops. Thus,farmers who do not aware of the,long-run price trends are faeedwith a high deg~ee of priee uneertainty,However, eoefficients ofrandom variation are mueh lowerthan coeffieients of variation.c - Gross income uneertainty:Gross income variabilityresults fröm the interaction ofyield and price. Sİnee yİeId variabilityis higher than priee variabi·"lity for almost aU crops, the mostiınportant faetor eontribııting togross income variability of cropsis the variahility of yields.Because of unce~tainty, praductionplanning is frequentlyimperfect. in order to lessen incômevariabiIity, farmers applycrop diversification, liquidity. andflexibility. This results in a mis~allocation of productive resources.Some means of lessening uncertaintyand its economic effectsare: a) credit policy, b) decreas~ing the dependanceof farming onnatural conditions, c) agriculturalinsurance, and d) forward pric- .ing.