Namų ūkių vartojimo modeliavimas

LTStraipsnyje teoriškai nagrinėjami namų ūkių vartojimo kitimo dėsningumai ir siūlomas empirinis modelis, paaiškinantis Lietuvos namų ūkių vartojimo išlaidų kitimą 1995-2006 m. Teorinėje dalyje apžvelgiamos pagrindinės vartojimo teorijos ir jas atitinkantys empiriniai modeliai, vertinamos jų taikymo galimybės. Empirinėje dalyje patvirtinama, kad Lietuvos namų ūkių vartojimo išlaidų kitimas neatsiejamas nuo namų ūkių pajamų kitimo. Atliekamo modeliavimo rezultatai bent iš dalies atitinka Milton Friedman iškeltos nuolatinių pajamų hipotezės pagrindinius principus. Straipsnyje daug dėmesio skiriama maždaug nuo 2003 m. prasidėjusiam Lietuvos namų ūkių vartojimo bumui paaiškinti, jis siejamas su finansų rinkos pokyčiais, t. y. išorinio finansavimo priemokos sumažėjimu ir gerokai padidėjusiu bankų kreditavimu. [Iš leidinio]Reikšminiai žodžiai: Namų ūkis; Vartojimas; Kreditas; Household; Consumption; Credit; Namų ūkis; Išorinis finansavimas; Household; External financing.

ENIn Lithuanian academic literature the analysis of private consumption, at the macroeconomic level, is relatively scarce and mostly stands as an integral part of larger structural macroeconomic models. In the current paper we aim to analyse consumption in some greater detail. Hence due attention is paid to general theoretical discussion of consumption determinants, which were barely discussed in Lithuanian economic literature before. We review some of the seminal theories of consumption, their most popular modern spin offs, touch upon various aspects of empirical implementation of modern theoretical models and discuss caveats of paving the bridge between theory and empirical regularities. We also express the view that against the background of financial liberalisation and the ongoing major structural changes in the Lithuanian economy, standard theories – including Keynes’s AIH, Friedman’s PIH, as well as the modern representative agent-based approaches – in their pure form are not well-suited to explain the recently observed consumption boom. Conducted data analysis confirms the need to depart from traditional theoretical models and apply hybrid empirical counterparts that blend various ideas from different theories. In our attempt to understand the recent surge of private consumption expenditure, we particularly emphasise the role of developments in the financial market. During the analysis period spanning from 1995 to 2006, private consumption expenditure exhibited a structural brake in 2003 associated with a sharp acceleration of consumption from that time onwards.The timing of the structural brake roughly coincided with the start of the credit boom. In the paper we discuss possible reasons why the two may be linked to each other, and possible explanations include an intertemporal shift in consumption facilitated by bank credit, household perceptions of rising permanent income and/or weakening precautionary saving motive owing to strong credit-fuelled income growth, and complementary acquisition of housing appliances in the wake of the credit-driven housing boom. The proposed model is of the error-correction form. In the cointegrating equation, private consumption is regressed on the disposable income but the equation is also augmented by inclusion of external financing premium, defined as the difference between bank loan and deposit rates, and net credit flows to the private nonfinancial sector, defined as credit financed by means other than time deposits. The fostering effect of financial liberalisation, relative cost of external financing and credit growth on consumption processes is confirmed by significant regression coefficients in the cointegration regression. In the difference equation of the error-correction model only disposable income and its dynamics in the prior four quarters matter, whereas financial variables are insignificant, apparently reflecting a somewhat loosely-structured nature of credit feeding into the real economy.Regarding the relationship between consumption expenditure and disposable income, slightly more than one half of a quarterly increase in the disposable income is consumed in the same quarter, and it takes about four more quarters before this income gain is (almost) fully consumed. As mentioned before, consumption expenditure fluctuations are affected by recent changes in income. Model results fit quite closely to the general ideas of Friedman’s PIH. According to the PIH, consumers differentiate between permanent and transitory changes of disposable income, expenditure closely tracks permanent income dynamics, and consumers form adaptive expectations of the permanent income component. Consumption and income relationship confirmed by our simple empirical model can be interpreted in the said line of reasoning. In addition, conducted empirical analysis of the Lithuanian case does not lend support to the popular theoretical principles of optimal intertemporal consumption smoothing and no evidence of positive relationship between consumption growth and interest rates was found. [From the publication]