우리나라 경제의 잠재성장 및 경기변동에 관한 분석

오형석 ( Hyoung Seok Oh ) 한국금융연구원 2007 금융연구 Vol.21 No.1

본 연구는 최근 우리나라 경제가, 성장잠재력이 지속적으로 낮아지는 가운데 경기의 진폭은 매우 확대되고 있는 상황을 분석하고자 하였다. 이에 따라 본고는 먼저 외환위기 이후 평균 잠재성장률 및 경기변동성에 통계적인 변화가 발생했는지를 실증분석하였다. 3-State Markov Switching 모형을 이용하여 잠재성장률의 평균 및 GDP갭의 조건부 분산을 분석한 결과, 최근으로 올수록 잠재성장률은 크게 하락한 가운데 GDP갭의 진폭은 매우 확대되었음을 확인하였다. 또한, 본고에서는 "성장잠재력 약화" 및 "경기변동성 심화"라는 실증분석 결과에 대해 총공급-총수요 측면에서 원인을 분석하고자 하였다. Blanchard & Quah(1989)가 제시하고, Koichiro & Naohisa(2002)가 발전시킨 구조 VAR모형을 이용하여, 우리나라의 거시경제에 발생하는 충격을 국내공급충격, 세계공급충격, 국내수요충격으로 구분하여 분석을 진행하였다. 분석결과, 외환위기를 거치면서 국내공급충격이 실물경제에 미치는 파급효과는 크게 축소된 반면, 세계공급충격의 영향력은 확대된 것으로 나타났다. 또한, 국내수요충격의 파급효과는 단기에 크게 증대된 것으로 분석되었다. 세계공급충격은 세계적인 기술확산에 따라 실물경제 파급효과가 증대된 것으로 나타났으나, 이를 우리나라만의 특징적인 현상으로 해석하기에는 무리가 있다. 국내공급 측면에서는 외환위기 이후 국내투자부진, 노동공급축소 및 IT산업의 낮은 생산파급 효과 등으로 산출량에 미치는 효과는 이전기간에 비해 크게 하락한 것으로 나타나 잠재성장률 하락에 크게 기여한 것으로 보인다. 한편, 수요충격은 외환위기 이후 산출량에 미치는 효과가 매우 커진 것으로 나타났는데, 이는 정부의 단기성 경기부양정책 및 IT산업의 비중 확대 등으로 인한 민간소비 및 수출의 변동성 확대에 기인하는 것으로 판단된다. 본고에서는 단기적인 경기변동을 완화시키는 동시에 약화된 성장잠재력을 회복시키기 위해서 다음과 같은 정책적 시사점을 도출하고자 한다. 정부는 경기변동을 심화시키는 단기성 경기부양정책을 지양하고, 기업들의 국내설비투자를 유인하기 위한 유효성 있는 정책을 시행해야 할 것으로 보인다. 또한, 국내 IT산업과 관련한 소재부품 산업에 대한 적극적인 육성정책이 필요하며, 차세대 성장동력산업을 발굴·육성시키는 일도 서둘러야 할 것이다. 마지막으로, 중앙은행은 물가가 안정된 상황에서도 여타 부문의 불균형이 발생할 경우 선제적인 정책대응을 통해 안정적인 경제성장을 유도해 나가야 할 것으로 판단된다. Since the currency crisis in 1997, South Korea has been losing its economic vitality with dramatically shrunken consumption and investment and continued slowdowns. South Korea`s economic volatility has expanded, experiencing repetitive recoveries and recessions after the strong recoveries in late 1999-early 2000. There are also growing concerns about weakening growth momentum. This paper analyzed the structural break in potential growth rate and volatility of GDP-gap using 3-State Markov Switching model and also empirically studied if there existed structural break in the response of the output to the supply-demand shock using the structural VAR model proposed by Blanchard and Quah. The analyses shows that the level of potential growth rate is declining and economic fluctuations are getting more volatile after the crisis in South Korea. In the mean time, the analysis on the supply-demand reveals that response of output to the world supply shocks increase while that to the domestic supply shocks decrease. The response of output to the domestic demand shocks go up in the short run but go down in the long run. These findings suggests that South Korea concentrates its effort on dissolving overall economic uncertainties and recovering growth momentum.

칼만필터를 이용한 우리나라의 중립금리 추정

오형석 ( Hyoung Seok Oh ) 한국금융연구원 2014 금융연구 Vol.28 No.1

Wicksell defined the natural rate in his book published at 1898 like this. There is a certain rate of interest on loans which is neutral in respect to commodity prices and tends neither to raise nor to lower them. From the recent point of view, Wicksell`s definition of the natural rate can be interpreted as the real interest rate consistent with output converging to potential, where potential is the level of output consistent with stable inflation. In many countries involving Korea, short-term interest rate has become the primary monetary policy instrument. Under this monetary policy regime, natural rate can provide a criteria for evaluating the stance of monetary policy and represent a medium-run real rate anchor for monetary policy (Laubach and Williams. 2003). If the real policy rate is above (below) the natural rate, we can evaluate the monetary policy stance as contractionary (stimulative). Therefore, if the real policy rate remain at the level of natural rate, there may be no pressure to boost or shrink economy from the monetary policy stance. Above this, the gap between real policy rate and the natural rate can be used as an indicator for future inflation (Neiss and Nelson, 2003). In order to estimating the natural rate, various methods are used. First, simple average of long-term real policy rate is mainly used by financial market participants. This method is very easy to get the natural rate, but the level of natural rate may be differ according to the sample period (Ferguson, 2004). Second, Kalman filter method is broadly used by many central banks and international organizations. This method can consider economic factors of determining the natural rate and time varying character of the natural rate. However, estimates of a time-varying natural rate by Kalman filter method may be very imprecise (Laubach and Williams, 2003). Finally, estimates of the natural rate from DSEG model (Smet and Wouters, 2007) and TIPS (Bomfim, 2001) are also used. In this paper, I use the model developed by Laubach and Williams (2003) to estimate the natural rate in Korea. This model is composed of IS equation, Phillips curve equation, Natural rate equation and so on. Especially, the natural rate is deeply related to the trend growth rate owing to the theoretical linkage between these two variables. And the trend growth rate and the natural rate are designed to have time-varying character because economic theory implies that the natural rate varies over time in response to shift in preference and technology (Laubach and Williams, 2003). Because the level of potential output, its trend growth rate and the natural rate are all unobservable, the Kalman filter method is applied to jointly estimate these variables. The data for estimating this model is quarterly basis and estimation period is from 1991:1 to 2012:4. I find that the natural rate shows significant variation in Korea. Variation in the trend growth rate is an important determination of change in the natural rate, as predicted by economic theory and described by related literatures like Laubach and Williams (2003). According to the decline of the potential GDP growth rate in Korea, the natural rate has been also steadily declined over the past twenty years. Judging the monetary policy stance from the gap between real policy rate and the estimates of natural rate since 2000, the stance of policy appears stimulative during the year of 2001, 2004, 2009. Especially, the expansionary policy stance after global financial crisis appears much stronger for a long time. On the other hand, the policy stance from the end of 2006 to the first half of 2008 appears contractionary to prevent high inflation. Judging from the gap between real policy rate and the natural rate, the Bank of Korea has conducted monetary policy considering global and domestic economic conditions sufficiently to stabilize the business cycle and inflation.

우리나라 장기금리 기간프리미엄 분석 및 정책적 시사점

오형석 ( Hyoung Seok Oh ) 한국금융연구원 2020 금융연구 Vol.34 No.4

본 연구의 목적은 중앙은행이 통화정책 운영에 있어 정책금리 측면의 대응여력이 부족해져 양적완화 등 비전통적 통화정책수단이 필요할 경우에 대비하여 비전통적 통화정책의 핵심 파급경로인 장기금리 기간프리미엄 분석을 통해 중앙은행 자산매입의 파급효과를 예상해 보고 정책적 시사점을 도출하기 위함이다. 이에 따라 본고는 국내외 주요 선행연구 등을 참고하여 장기금리 기간프리미엄에 영향을 미치는 주요 대내외 요인들을 선별하여 실증분석을 실시하였다. 분석결과, 우리나라 장기금리 기간프리미엄에는 미래 경제성장과 물가에 대한 장기 전망, 장기 전망시수반되는 불확실성 등의 거시경제 여건, 정부의 국채공급규모, 장기유동성 증가율, 주가 수익률 등의 대내요인 뿐만 아니라 글로벌 유동성, 외국인 국채보유비중, 미국 장기금리 기간프리미엄 등의 대외요인이 복합적으로 영향을 미치고 있는 것으로 추정되었다. 특히 금융위기 이후 꾸준히 증가해 온 외국인 국채보유규모 관련 변수는 본고의 다양한 분석에서 모두 통계적으로 유의한 것으로 추정되었는데, 동 변수는 중앙은행의 자산매입 정책과 매우 유사한 파급경로를 지니고 있다는 점에서 중앙은행이 양적완화를 도입할 경우 채권시장에서 정책효과가 유의하게 나타날 수 있을 것이라는 시사점을 도출할 수 있었다. 다만, 매우 다양한 요인들이 장기금리 기간프리미엄에 영향을 미치는 것으로 나타난 만큼 양적완화 도입시의 효과는 국내외 금융·경제여건 변화에 따라 상이하게 나타날 것으로 예상된다. 한편, 중앙은행의 양적완화는 민간신용 증가 등을 유발하여 금융불균형을 증대시킬 가능성도 배제할 수 없는 만큼, 정책시행에 따른 효과와 부작용 발생가능성 등을 종합적으로 고려하여 시행여부를 판단할 필요가 있을 것으로 보인다. The term premium means an excess return that investors demand to compensate for holding long term bond. Therefore, long term economic outlook and uncertainty are main drivers of the term premium because these factors can affect the risk of long term bond price. In addition, unconventional monetary policy can be an important factor of term premium. If a central bank purchases long duration government securities on a large scale, this policy may reduce the amount of long-term securities in the bond market. This can put downward pressure on term premium in long term yield. After the crisis of COVID-19, many central banks have lowered policy rates to their effective lower bounds. Under this situation, central banks can use quantitative easing to make financial conditions more accommodative. Therefore, term premium has gained attention in the sense of an unconventional policy tool. This research focuses on getting policy implications for an unconventional monetary policy in Korea by analyzing the determinants of term premium and finding that what factors have influenced change in the term premium of Korean 10-year government bond yield after global financial crisis. Term premium is estimated by ACM (2013) method like FRB of New York. The empirical results suggest five main conclusions. First, macroeconomic uncertainty influences the behavior of term premium. In addition, long term expectations of inflation and growth are associated with the change in the term premium. Second, the increase in global liquidity due to quantitative easing policy of major countries has an important role in the change of Korean term premium. In addition, the U.S. term premium has a significant impact on Korean term premium. Third, long-term money growth has an important role for the decline in term premium. As the life expectancy in Korea is increasing faster than expected, the individual want to save more, which lead to the increase in long-term money and the demand of safe asset, for example long-term government bond. The fourth conclusion is that the increase in government bond issuance has upward pressure on the term premium. Finally, the increase of foreign investment on Korean government bond is the primary source of the fall in term premium during recent decade. Because the effect of increasing in foreign holdings of Korean long-term bond is very similar to that of large scale bond purchases by central bank, this estimation result implies that quantitative easing policy in Korea might be effective in long-term bond market.

Polyol Process를 통한 PEM Fuel Cell용 Pt/C촉매 제조

오형석(Oh, Hyoung-Seok),김한성(Kim, Han-Sung) 한국신재생에너지학회 2006 한국신재생에너지학회 학술대회논문집 Vol.2006 No.11

Carbon-supported Platinum (Pt) is the potential electro-catalyst material for anodic and cathodic reactions in fuel cell. Catalytic activity of the metal strongly depends on the particle shape, size and distribution of the metal in the porous supportive network. Conventional preparation techniques based on wet impregnation and chemical reduction of the metal precursors often do not provide adequate control of particle size and shape. We have proposed a novel route for preparing nano sized Pt colloidal particles in solution by oxidation of ethylene glycol. These Pt nano particles were deposited on large surface area carbon support. The process of nano Pt colloid formation involves the oxidation of solvent ethylene glycol to mainly glycolic acid and the presence of its anion glycolate depends on the solution pH. In the process of colloidal Pt formation glycolate actsas stabilizer for the Pt colloidal particle and prevents the agglomeration of colloidal Pt particles. These mono disperse Pt particles in carbon support are found uniformly distributed in nearly spherical shape and the size distribution was narrow for both supported and unsupported metals. The average diameter of the Pt nano particle was controlled in the range off to 3 nm by optimizing reaction parameters. Transmission electron microscopy, CV and RRDE experiments were used to compliment the results.

전단연결 앵글의 배치에 따른 콘크리트-강 합성보 휨 강도에 관한 연구

오형석(Oh, Hyoung Seok),신형엽(Shin, Hyeongyeop),강현구(Kang, Thomas H.-K.) 한국콘크리트학회 2020 한국콘크리트학회 학술대회 논문집 Vol.32 No.1

학교시설 복합화에 대한 소고(小考)

오형석(Oh, Hyoung-Seok) 한국교육시설학회 2015 敎育施設 Vol.22 No.4

전단연결 앵글의 배치에 따른 콘크리트-강 합성보 전단강도에 관한 연구

오형석(Oh Hyoung Seok),신형엽(Shin, Hyeongyeop),강현구(Kang, Thomas H.-K) 한국콘크리트학회 2019 한국콘크리트학회 학술대회 논문집 Vol.31 No.2

Stephen Wise Performing Arts Center

오형석 ( Oh Hyoung Seok ) 한국기초조형학회 2019 한국기초조형학회 작품집 Vol.2019 No.1

애니메이션 테크닉에 기반한 시공간 요소의 건축적 재해석과 디지털 디자인 프로세스에 관한 연구

오형석(Oh Hyoung-Seok) 대한건축학회 2010 대한건축학회논문집 Vol.26 No.6

Contemporary process in architectural field tries to focus indeterminate and non-hierarchical structure rather than predetermined categorical rules because it can avoid the conclusive approaches and limited representations of personal analogy or metaphor. Innovative conceptions of time and space in various fields have helped unexpected value of relations unveil without intention. Recent digital media encourages this tendency to generate more potential and temporal diagrams of relations rather than just curvilinear forms. Animation based technique is actually spatial simulation of accidental dynamics through time which can convert to visual diagram and simulate non-hierarchical value structure. This study shows some examples of new paradigm how to deal with the time-space and event in various fields such as fine arts, performing arts and mass medias and introduces the method of animation based technique via an architectural project to enlighten the relation of programs and visual representations.

나의 대학생활 답사기

오형석(Hyoung Seok Oh) 대한토목학회 2021 대한토목학회지 Vol.69 No.5