Türkiye tüketim harcamaları davranış denklemleri (1987)
The Behavioral equations of Turkish consumption expenditures (1987)
Yazar: RAZİYE SELİM
Danışman: PROF. DR. ÜMİT ŞENESEN
İstanbul Teknik Üniversitesi / Fen Bilimleri Enstitüsü / Sayısal Yöntemler Ana Bilim Dalı
Derece: Yüksek Lisans, 1993
Konu: İşletme = Business Administration
Dizin: Mikroekonomi = Microeconomy ; Tüketim harcamaları = Consumption expenditures ; Türkiye = Turkey ; İşletme mühendisliği = Business engineering

Özet:
Hanehal ki arının tüketim harca/naları davranışının analizi, mikroekonomideki gelir-tüketim esrilerinden oluşturulan gelir artışlarına karcı bir inaldan talep ©dilen miktarlardaki değişmeyi gösteren "Engel Esrileri" aracılığıyla yapılmaktadır» Bu noktada, Engel eğrileri nin uyum gösterdiği fonksiyon tipinin seçilmesi önemli dir. Seçilen fonksiyondan hesaplanan esneklik çeşitli mallar/mal gruplarının "lüks" veya "zorunlu" mallar ola rak sınıflandırılmasında kullanılır» Engel eğrileri ve gelir esnekliklerinin incelenme si hanehalkı tüketim harcamalarını gösteren yatay- kesit verileri üzerinden yapılır. Bu çalınmada Devlet İsta tistik Enstitüsü' nün 19S7anehalkı Tüketim Harcamaları Anket Sonuçları 'ndan alınan veriler kullanılmıştır. Hanehal ki arının gıda, giyim, konut v.b. gibi il harcama türüne yaptıkları harcamaların bacımla değişken, toplam harcamaların açıklayıcı demişken olarak alındığı 9 farklı fonksiyon kalıbı denenerek, uygun kalıplar se çilmiştir. Denklemlerin tahmininde, toplam harcamalara göre gruplanroıs verilerle çalıştığımız için Tartılı En Küçük Kareler Yöntemi kullanılmıştır. Tüketim harcama davranırı, hanehal kının kent veya kır kesiminde yasıyor olmasına göre farklılasabilir» Kent-kır ayrımının hangi mal gruplarına yönelik harcama davranışını etkilediğinin bulunabilmesi için Türkiye ve rileriyle yapılan tahminler kent ve kır verileriyle de ayrı ayrı yapılmıştır. Toplam harcama esneklikleri her mal grubu için en yüksek uyum sağladığı denklem üzerinden hesaplanmıştır. Bıda ve konutun toplan» harcsma esnek 1 içi i ' den küçük, giyimin i ' den büyük bulunarak teorideki Engel Kanunları doğru 1 anmıştır. Mal gruplarının esneklikleri karşılaştırıldığında gıdanın 1 ' den küçük esneklikle zorunlu harcamalar, gi yim, ev eşyaları, evle ilgili bakım hizmet, ulaştırma haberleşme, kül tür-egi t im~eQl ence ve diğer harcamaların 1 ' den büyük esneklikle lüks harcamalar arasında yeraldı- Qı görülür. Lokanta, sağlık ve kişisel bakım harcama esneklikleri ise i dolayındadır. Alt gelir düzeyinden üst gelir düzeyine gidildi ğinde gıda, giyim, saÇılık ve diQ>er toplam harcama esnek likleri düşmektedir. Sağlık ve lokanta harcama türünde gelir düzeyleri arasında fark yoktur..*- via

Abstract:
The main objective o-f this study is the analysis o-f household consumption pattern in Turkey. De-fining the luxuries and nesessities in Turkish consumption pattern and the differences between rural and urban consumption patterns are the subject of the study. To what extend the Engel laws can explain consumer pattern of Turkish households. Demand for a commodity is the -function o-f the tastes, the price of the commodity and the consumer income» Assuming that tastes and the commodity prices remain unchanged the consumer adjusts his equilibrium consumption basket in response to the changes in his income. The in-fl uences of the changes in consumer income on quantity o.-f demand is shown by income- consumption curve. Using' the income-consumption curves the quantity o-f demand on a commodity can be shown at certain levels of income. German economist Ernst Engel, who investigated the relationship between the groups of consumption and income is the -first economist studied this relationship. A-fter the Engel, the curves which show this relationship is known as Engel curves. According to Engel Lawss - Food is the most important item in the household consumpt ion. - With increasing income the -food consumption have less share in total consumption. ~ The share o-f the clothing and housing is constant while share o-f luxuries increases with increasing income. To find the most appropriate -functional -form for Engel curves has great importance in literature» The fuctional forms are generated by using di-fferent utility -functions» One o-f these -forms is linear form, which generate from Additive Utility Function. I-f we assume that the attitude towards determining the quantity of consumption of a certain good are independent from the quantity o-f consumption of other goods, the Additive Utility Function can be deduced. vi 1 1SUMMARY The main objective of this study is the analysis of household consumption pattern in Turkey» Defining the luxuries and nesessities in Turkish consumption pattern and the differences between rural and urban consumption patterns are the subject of the study. To what extend the Engel laws can explain consumer pattern of Turkish households» Demand for a commodity is the function of the tastes., the price of the commodity and the consumer income» Assuming that tastes and the commodity prices- remain unchanged the consumer adjusts his equilibrium consumption basket in response to the changes in his income» The influences of the changes in consumer income on quantity of demand is shown by income-consumption curve» Using the income-consumption curves the quantity of demand on a commodity can be shown at certain levels of income» German economist Ernst Engel 3 who investigated the relationship between the groups of consumption and income is the first economist studied this relationship. After -th.e Engel, the curves which show this relationship is known as Engel curves. According to Engel Laws; - Food is the most important item in the household consumption " - With increasing income the food consumption have less share in total consumption» - The share of the clothing and housing is constant while share of luxuries increases with increasing income» To find the most appropriate functional form for Engel curves has great importance in literature. The fuctional forms &re generated by using different utility functions. One of these forms is linear form» which generate from Additive Utility Function» If we assume that the attitude towards determining the quantity of consumption of a certain good &y~e independent from the quantity of consumption of other goods, the Additive Utility Function can be deduced. - VilX -The function which contains the Quantity of consumption of commodity is Direct Utility Function. If the maximum available utility is given by function of the commodity- price and the income, this function is called Indirect Ut i 1 i t y Fu ne t i o n. The semi-log form is used by Prais and Houthakker for food expenditure» This study considers nine different functional forms to explain Engel curves. Using the total expenditure as independent variable and the expenditure on a certain commodity as dependent variable these nine functional forms are tested for Turkish households» To eliminate the error caused by the understatement of income, instead of total income, the total expenditure is used as explanatory variable» Another reason -For this is that the total expenditure figures reflect the permanent income of the household» The results of 1987 Household Income and Consumption Expenditures Survey, Which conducted by The State Institute of Statistics, ars used as the source of data» The data s.re grouped into 21 income classes and defined eleven expenditure categories» Unfortunately the part of data which belong to the upper income groups have some deficiencies mainly due to the handicaps faced during the survey» In order to overcome these deficiencies we excluded three (out of 215 highest income groups from our analysis» The findings ars only valid for the remaining 18 income groups but this should not create a false alarm since the excluded households make up only 0.05 percent of the total. In other words the share of the number of households included in this study is 99.95 percent, of the national total» The data were analysed for urban and rural households seperately as well as all combined together» When the grouped data are used in a model,, regression analysis results show beteroscedastic disturbances» The use of The Method of Ordinary Least Squares on grouped data gives inefficient parameter estimators and inconsistent estimator variances» Since our data are grouped in the above mentioned Survey The Method of Weighted Least Squares forced upon us, which gives consistent and efficient parameter est i mat or s »The mean value of each expenditure groups ara used in the calculations of Engel curves. To incorporate the group means into calculations, formula o-F estimators are adjustec with respect to heteroscedast ist ic variance» The regression analysis is carried out by group means weighted with the number o-F observations in each expenditure group,, R35 is the goodness o-F -Fit measure, which measures the proportion o-F the weigted sum o-F.squares o-F the dependent variable., explained by the model. Using nationwide, urban and rural data -For eleven expenditure categories nine -functional -Forms ars estimated through regression analysis» ft functional -form is selected, re-ferring to several criteria., such as the significance level co efficient estimates, goodness of fit, etc. as the best one for each expenditure category» The amount of the changes in demand as response to the changes in income can be determined by the elasticity of income which are calculated on the basis of Engel curves. The elasticity of income is the ratio of percentage change in income. The commodities can be classified on the basis of their income elasticites» If the percentage change in income is smaller than the percentage increase in demand (if income elasticity is higher than. 1 ) for a commodity- then it is called a "luxury" - If for a commodity the income elasticity is less than if then it is called a. "necessity". The total exoenditurs elasticity (instead of income elasticity) is calculated for each expenditure aax. eg o r y. The double- log form has constant elasticity on the whole range of bial expenditure axis. "or the other forms, 3 different elasticity values which represent lower, middle and upper total expenditure level are calculated» Total expenditure elasticities nave been estimated at the mean values of dependent and independent variables in the previous works» The findings of this study confirm the Engel Laws. The food is the major item of Turkish household» Food expenditure share in total expenditures is almost 1/3. Food, housing and clothing make up approximately 2/3 of total expenditures. An important piece of information obtained from these models is total expenditure elasticity of eachexpenditure category» The elasticity results can be compared with respect to three different dimensions. These 3.rs the comparisons; a.) Between commodity categories;, b. ) Between lower, middle and upper income levels, c. ) Between urban-rural areas. The elasticities estimated by keeping the income level constant nationwide elasticities can be used for classification of commodity categories as luxuries or necessities. Food and housing expenditures are necessities with elasticities less than unity. Restaurant f health-care and personal expenditure elasticities are around unity» For the other commodity categories (clothing, furniture, services, transportation and communication, culture education and entertainment, others) have elasticities which ar& greater than unity implying that they are luxuries. These results showns great similarities with previous studies on the 1978-79 data (Tansel, 1986 and Günlük Senesen, 19B7). The second comparison is made between elasticities of different income levels. Elasticities are estimated at three different income levels for each model excluding double-log model. The total expenditure elasticity of food consumption declines as income increases,. In lower income level a Percentage increase in income creates a higher percentage increase? in food expenditures than in h i g her i ncome 1 eve I « For clothing, housing and other expenditures the same proposition can be raised. For health-care expenditure there is no difference between the three elasticities. It can be concluded that household consumption pattern for health-care is the same for all income levels. For restaurant expenditure the situation is similar to the one with health-care expenditure. At the last stage, urban, rural data are used to determine whether any significant differences noted in the structure of consumer pattern between the rural and the urban consumers. i -No sign i -fi cant differences are -found between the total expenditure elasticities of -food -for the rural and t he u r ba n house ho 1 ds. The clothing total expenditure elasticity is greater in rural households. Interestingly enough, Restaurant -fits into "luxury category" in urban areas. whereas it is one of the items of "necessities" in rural expenditure. Therefore one should redefine "luxuries" for rural and urban areas.