Fikr.ap

menimcha senga bu kanal yoqib tushadi…

eminem haqida maqola.

Requiem for dream.
Persona.
The house that Jack built.

uchlasa ham psixopatlar haqida, og'ir kinolar ekan, to'g'risi nima sabab taklif qilishganini ham tushunmadim.

oxiri yaxshi yakun bo'ldi.

This study identified and compared the upgrading impacts for the quantity, quality, and structural aspects of transport infrastructure on regional economic growth in China from 2007 to 2015, when the country was approaching the upper-middle income stage of development. This is the first study to consider government development strategies in a transport infrastructure impact evaluation framework for China. We constructed a unique dataset to describe the three aspects of the transport infrastructure, and in contrast to recent literature, we selected provinces as the geographic units to alleviate concerns about SUTVA violations [28]. To address concerns about reverse causality and account for lagged responses in economic growth to any exogenous shock including transport infrastructure, we adopted the system-GMM estimator for dynamic panel data and obtained consistent and unbiased parameter estimates [32,33,34,37,60]. We also compared our results with those in the existing literature, focusing on the differential impacts of various aspects of transport infrastructure on regional economic growth in China at different economic development levels. This approach yields new insights.
Our analysis led us to some general conclusions about the effects of transport infrastructure on growth. First, it appeared that transport infrastructure wasstill significantly contributing to economic growth in China, even as the country had entered the upper-middle income stage. Second, quality improvements in roadways and railways (measured by expressways and HSR development) and structural upgrading of the transport infrastructure (measured by the increasing share of government expenditure for transport) significantly contributed to growth at this development level. However, we didnot find a significant positive impact for overall quantity expansion of the land transport network. Third, government development strategies that defy local comparative advantages not only lead to a lower per capita GDP growth rate but also potentially restrict the contribution of transport infrastructure. Lastly, regional heterogeneity for Western China could differ across transport modes, particularly with respect to goods versus passenger transport and roadways versus railways.
This research enhances our understanding of transport infrastructure impacts on economic growth in China and can inform national transport infrastructure policy. The results are specific to China’s context but could be useful for policymakers in other emerging economies and developing countries that are experiencing comparable economic growth and infrastructure development patterns. Economic growth is central to China’s economic development mission, and our study suggests that public investments in national high-quality roadways and railways as well as government expenditure for transport maintenance to improve service efficiency can stimulate aggregate economic growth, as China reaches the upper-middle income stage. Compared with the earlier and most recent literature, we found that overall, different aspects of transport infrastructure had heterogeneous impacts on growth depending on the economic development level. Moreover, to ensure that transport infrastructure investment will guarantee growth, government development strategies that are favorable to the overall economic conditions are a vital policy prerequisite.
From a broader perspective, future studies could pay more attention to the function of transport infrastructure to achieve the Sustainable Development Goals adopted by all United Nations Member States in 2015. Moreover, new infrastructure, compared to traditional infrastructure such as roads, railways, and bridges, are built on advanced technology and digitization. Future research may also analyze how the current system of information and communications infrastructure can be used to develop the infrastructure under the paradigm of Industry 4.0

Tizimli Generalizatsiyalangan Momentlar Usuli (System-GMM) dinamik panel ma'lumotlari modellarini baholash uchun ishlatiladigan ekonometrik texnikadir. Bu farqlar-GMM baholovchisining kengaytirilgan shakli bo‘lib, samaradorlikni oshirish va endogenlik, tashlab ketilgan o‘zgaruvchilar va o‘lchov xatolaridan kelib chiqadigan potensial noxolisliklarni bartaraf etishga mo‘ljallangan.

Tizimli-GMM farqlar tenglamasi bilan daraja tenglamasini birlashtiradi. Farqlar-GMM o‘zgarmas ta’sirlarni olib tashlash uchun birinchi farqlarni ishlatadi, ammo bu instrumentlarning kuchsizlanishiga olib kelishi mumkin. Tizimli-GMM esa daraja tenglamasidan qo‘shimcha moment shartlarini ishlatib, samaradorlikni oshiradi.

Bu usul endogen o‘zgaruvchilar bilan ishlashga imkon beradi, chunki ichki instrumentlar sifatida o‘zgaruvchilarning kechiktirilgan qiymatlaridan foydalanadi. Bu dinamik modellar ichida o‘zaro bog‘liqlik muammosini hal qilishda muhim rol o‘ynaydi.

Tizimli-GMM kombinatsiyalangan tenglamalar orqali ko‘proq yaroqli instrumentlar hosil qiladi va instrumentlar haddan tashqari ko‘payib ketish muammosini kamaytiradi.

Bu usulning muhim statistik testlari mavjud. Hansen testi ortiqcha identifikatsiya (instrumentlarning yaroqliligi) tekshiradi. AR(1) va AR(2) testlari esa xatolik atamalarida ikkinchi tartibli autokorrelatsiya mavjudligini tahlil qiladi.

Tizimli-GMM makroiqtisodiyot va moliya sohalarida keng qo‘llaniladi, xususan, iqtisodiy o‘sish modellarini, korxonalar samaradorligini va siyosat tahlillarini baholashda ishlatiladi. Bu usul endogenlik mavjud bo‘lgan panel ma’lumotlari tadqiqotlarida qo‘llanadi.

Ushbu usul Stata dasturida xtabond2 buyrug‘i, R dasturida esa plm va pgmm paketlari orqali amalga oshiriladi.

China’s evidence suggests that the transport infrastructure impact differs according to development levels and transport infrastructure attributes. For example, Demurger [7] estimated the impact of transport infrastructure quantity (railway, road, and inland navigable water network length per square kilometer) from 1985 to 1998, when China was a low-income country. The author found that the overall transport quantity had a positive effect on provincial growth, but the impacts decreased with the level of economic development. In a similar research period, Fan and Chan-Kang [8] found that from 1982 to 1999, low-quality roads (mostly rural) rather than high-quality ones (expressways) contributed more to GDP, urban GDP, and poverty reduction. Hong et al. [9] considered both the quantity and quality of transport infrastructure and showed that from 1998 to 2007 (after China became a middle income country), land and water transport’s growth impacts were greater than those from airway transport. Lin [10] found that as China approached an upper-middle income level from 2008 to 2013, its HSR promoted urban employment and GDP. Other research has found that transport had zero or negative impacts on development outcomes. For instance, Faber [11] constructed hypothetical instruments and found that from 1997 to 2006, the National Trunk Highway System reduced county GDP growth. Qin [12] exploited an inconsequential units approach and found that from 2002 to 2009, railway speed upgrading reduced county GDP. Feng and Wu [13] showed a negative productivity effect from public infrastructure capital stocks across provinces from 1996 to 2015. Banerjee et al. [14] used an instrumental approach and system-generalized method of moments (GMM) and determined that from 1986 to 2006, the distance of a county from historical transport networks had no impact on per capita GDP growth. In sum, most previous studies have used either public infrastructure investments [15], transport investments [13], or roadway lengths [7] to measure transport infrastructure endowments, but these studies do not capture effects from transport infrastructure quality. Among studies considering both the quantity and quality of transport infrastructure, some identified an overall impact but did not distinguish between the two effects .

📑 Transport Infrastructure Development and Economic Growth in China: Recent Evidence fromynamic Panel System-GMM Analysis
✍ Xiao Ke , Justin Yifu Lin, Caihui Fu andYong Wang

ul yoshlikni yod aylash uchun…
ko’r.