مدل سازی اقتصادی رقابت، مالیات و رشد اقتصادی

The paper mainly examines the relationship between economic growth, tax policy and sectoral labor distribution in an endogenous growth model with expanding varieties. For analyzing these relationships, we consider an economy where three sectors of production are vertically integrated: final goods sector, intermediate goods sector and research sector. We show that the extent of imperfect competition in the intermediate products market affects both economic growth and the allocation of the available labor to all the sectors employing this input. The resources from capital taxation, which are used for financing research sector, have a U-shaped effect on growth and lead to a movement of the labor from research sector to final goods sector. Additionally, we show that if there exists a higher competitive structure in an economy, the probability of the positive effect of an increase in tax on growth gets higher.

In the last decades, the importance of the creation and diffusion of ideas to economic development has been well recognized. This fact is corroborated by increasing participation of the governments subsidizing R&D-activities. In order to observe the relevance of this public intervention, we analyze the effects of a subsidy financed by taxation to these activities on long-run economic growth and sectoral labor distribution, in addition to the effects of competition on them, using a generalization of Romer's (1990) and Grossman and Helpman's (1991: Ch. 3) endogenous growth model with expanding varieties of products. Alesina and Rodrik (1994) discuss the economic growth, taxation and income distribution in a one-sector endogenous growth. In this model they postulate that government spending is financed by a proportional tax on capital income. We carry this postulation into a three-sector endogenous growth model, but rather than discussing income distribution, we discuss impacts of competition and taxation on economic growth and sectoral labor distribution. Even though the R&D-based models of growth generally consider a R&D-technology that uses skilled labor as an unique input, we use a technology of innovation based on both subsidy devoted to R&D by the government and labor as an input. This structure leads us to discuss the channels through which capital income taxes affect resource allocation and growth and investigate the role of the government in the determination of an economy's long-run performance. Endogenous growth theory generates various predictions as to the relationship between competition and growth. In fact, those theoretical models can be categorized as suggesting that competitive market structures have monotone effects (e.g., Romer (1990), Aghion and Howitt (1992), Grossman and Helpman (1991)) or non-monotonic effects on innovation and productivity growth (Aghion et al. (2001), Aghion et al. (2005), Bucci (2003) and Bucci and Parello (2009)). While monotone models suggest that tougher competition has either positive or negative impact on innovation or growth, non-monotone models predict an inverted-U relationship between competition and innovation or growth. What we found out in the paper is compatible with the studies presenting monotone effect of competition on growth. We show that the extent of imperfect competition in the intermediate products (denoted by the substitutability degree between intermediate products) influences both growth rate and the allocation of the available labor to all the sectors positively. An increase in competition affects the growth rate of the final goods production in two positive ways. One of these is positive contribution of the increased subsidy to growth. The other positive effect is arising from an increase in the share of labor working in the research sector. Even though the direction of wages following an increase in competition is ambiguous, the combined effects of changes in the prices of intermediate goods and wage of workers lead to a decrease in labor share devoted to final goods sector and an increase in labor share devoted to research sector. In the paper the second important issue we are concerned with is the effects of (capital) income tax on growth and sectoral labor distribution. The effects of income taxation in the context of a two-sector endogenous growth model have been examined before by many authors. Some of these studies use numerical models to calculate the effect of tax reform on growth (e.g., Lucas (1990), Jones, Manuelli and Rossi (1993), Stokey and Rebelo (1995) and Hendricks (1999)). Some other studies, like Chamley (1992) and Mino (1996), search for analytically the effect of income taxation on growth. Almost all these studies conclude that an income tax has a negative effect on growth. However, in a study by Uhlig and Yanagawa (1996), it is shown that higher capital income taxes may lead to faster growth in an overlapping generation structure. In contrast to the literature mentioned above we find out that taxes have a hump-shaped effect on the steady-state growth rate. There are two counteracting factors that determine the direction of the change in growth rate. The first factor is positive subsidy effect on the research sector leading to an increase in growth rate. The second factor is negative labor share effect that arises from a change in the cost of labor and the cost of intermediate goods leading to the fall in labor share devoted to research sector. Consequently, the change in growth rate in the steady state depends on the size of these two counteracting effects. Nevertheless we show that if there is a higher competitive structure in an economy, the probability of the positive effect of an increase in tax on growth gets higher. The remainder of this paper is organized as follows. Section 2 describes the model. Section 2.3 derives the equilibrium of the model. Section 3 analyzes the theoretical effects of competition on economic growth and sectoral labor distribution. Similarly Section 4 searches for the theoretical effects of taxation on economic growth and sectoral labor distribution. Section 4 concludes.

We set up an endogenous growth model with expanding varieties in which the government finances the R&D sector through taxes imposed on capital. This structure leads us to discuss the channels through which capital income taxes affect resource allocation and growth and to investigate the role of the government in the determination of an economy's long-run performance. We show that while a decrease in the level of imperfect competition in the intermediate products market increases growth rate, it re-allocates labor from final goods sector to research sector. Our another finding is that taxes have a hump-shaped effect on the steady-state growth rate due to the combination of positive subsidy effect on research sector and a negative effect on the fraction of labor allocated to research sector. However, we also demonstrate that since an increase in competition level increases the threshold level under which the taxation has a positive effect on growth, the probability of positive effect of capital taxation on growth increases. Consequently, competition's both direct and indirect effects that reflect themselves in increasing the threshold tax rate are beneficial to growth. Hence, any appropriate policy to reduce market power may be good from this perspective. In fact this result is in accordance with the literature that shows a monotone effect of competition on growth. But we also show that competition shows its positive effect even through taxation in a more complex structure growth model. However, we have to mention that although we mainly show that the structure in which the economy works and taxation policy are essential in terms of growth and sectoral labor distribution, the results we obtain are not clear-cut, hence clearly more work is needed to resolve the theoretical ambiguities concerning the effect of structural parameters on growth.