Analysing the effects of fiscal policy and assessing its sustainability

This thesis presents three empirical analyses of the macroeconomic effects and sustainability of fiscal policy. Three key issues are examined: the transmission mechanism for fiscal policy shocks in Korea, the sustainability of government debt in three selected countries (Korea, the UK, and the US), and the effects of fiscal consolidation on macroeconomic activity. The main findings are as follows. First, government spending has a positive effect on the economy. Capital spending is likely to boost the economy more effectively than current spending. Second, there is a cointegrating relationship between the variables in Korea and the US, but not in the UK. That means fiscal policy in Korea and the US is sustainable, while fiscal policy in the UK is not. Third, fiscal consolidation is not likely to be expansionary in terms of GDP growth. The results also show that fiscal consolidation in time of high debt-to-GDP ratios, the spending-base, or high sovereign risk has fewer negative effects on economic growth than fiscal consolidation in time of low debt-to-GDP ratios, the tax-base, or low sovereign risk. The economic growth rate, government spending-based fiscal consolidation, low long-term interest rates, and higher sovereign risk have significant effects on reducing debt-to-GDP ratio

Effects of Fiscal Consolidation in 18 OECD Countries

This paper estimates the effects of fiscal consolidation on economic growth using panel datasets from 18 Organization for Economic Cooperation and Development (OECD) countries. The estimates of dynamic panel data Generalized Method of Moment (GMM) analysis show that fiscal consolidation is unlikely to be expansionary for GDP growth. Both Arellano-Bond difference GMM estimation and Blundell-Bond system GMM estimation suggest that fiscal consolidation exert negative effects on economic growth. Results do not support the expansionary fiscal consolidation hypothesis. In particular, our analyses find that fiscal consolidations during high debt-to-GDP ratios, based on spending cuts, or with high sovereign default risk exert less negative effects on economic growth than those during low debt-to-GDP ratios, based on tax hikes, or with low sovereign default risk

The Spitzer c2d Survey Of Nearby Dense Cores. VII. Chemistry And Dynamics In L43

We present results from the Spitzer Space Telescope and molecular line observations of nine species toward the dark cloud L43. The Spitzer images and molecular line maps suggest that it has a starless core and a Class I protostar evolving in the same environment. CO depletion is seen in both sources, and DCO(+) lines are stronger toward the starless core. With a goal of testing the chemical characteristics from pre- to protostellar stages, we adopt an evolutionary chemical model to calculate the molecular abundances and compare with our observations. Among the different model parameters we tested, the best-fit model suggests a longer total timescale at the pre-protostellar stage, but with faster evolution at the later steps with higher densities.NSF AST-0307250, AST0607793NASA NNX07AJ72GNational Research Foundation of Korea (NRF) government (MEST) 2009-0062865KOSEF R012007- 000-20336-0Astronom

Generation of nanovesicles with sliced cellular membrane fragments for exogenous material delivery

We propose a microfluidic system that generates nanovesicles (NVs) by slicing living cell membrane with microfabricated 500 nm-thick silicon nitride (SixNy) blades. Living cells were sliced by the blades while flowing through microchannels lined with the blades. Plasma membrane fragments sliced from the cells self-assembled into spherical NVs of similar to 100-300 nm in diameter. During self-assembly, the plasma membrane fragments enveloped exogenous materials (here, polystyrene latex beads) from the buffer solution. About 30% of beads were encapsulated in NVs,, and the generated NVs delivered the encapsulated beads across the plasma membrane of recipient cells, but bare beads could not penetrate the plasma membrane of recipient cells. This result implicates that the NVs generated using the method in this study can encapsulate and deliver exogenous materials to recipient cells, whereas exosomes secreted by cells can deliver only endogenous cellular materials. (C) 2015 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).X112015Ysciescopu

Impact of environmental changes on the dynamics of temporal networks

Dynamics of complex social systems has often been described in the framework of temporal networks, where links are considered to exist only at the moment of interaction between nodes. Such interaction patterns are not only driven by internal interaction mechanisms, but also affected by environmental changes. To investigate the impact of the environmental changes on the dynamics of temporal networks, we analyze several face-to-face interaction datasets using the multiscale entropy (MSE) method to find that the observed temporal correlations can be categorized according to the environmental similarity of datasets such as classes and break times in schools. By devising and studying a temporal network model considering a periodically changing environment as well as a preferential activation mechanism, we numerically show that our model could successfully reproduce various empirical results by the MSE method in terms of multiscale temporal correlations. Our results demonstrate that the environmental changes can play an important role in shaping the dynamics of temporal networks when the interactions between nodes are influenced by the environment of the systems.Comment: 10 pages, 8 figure