• Korean Journal of Agricultural Science
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• v.48 no.4
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• pp.797-806
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• 2021

As the number of scaled-up ranches increased and agile responses to market changes became possible, decision-making by Hanwoo cattle farms also began to affect short-term shipments. Considering the changing environment of the Hanwoo supply market and the response speed of producers, it is necessary quickly to grasp the forecast ahead of time and to respond accordingly in an effort to stabilize supply and demand in the Hanwoo market. In this study, short-term forecasting model centered on the supply of Hanwoo was established. The analysis conducted here indicates that the slaughter of Hanwoo males increases by 0.248 as the number of beef cattle raised over 29 months of age in the previous month increases by one, and 0.764 Hanwoo females were slaughtered under average conditions for every Hanwoo male slaughtered. With regard to time, the slaughtering of Hanwoo was higher in January and August, which are months known for holiday food preparation activities for the New Year and Chuseok in Korea, respectively. Simulations indicated that errors were within 10% in all simulations performed through the Hanwoo supply model. Accordingly, it is considered that the estimation results from the supply model devised in this study are reliable and that the model has good structural stability.

• Journal of the Economic Geographical Society of Korea
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• v.5 no.2
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• pp.187-207
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• 2002

This study investigates the wage determination process of regional labor markets in order to understand the regional dimension of labor market processes in Korean metropolitan cities. Since the financial crisis in late 1997, the interplay between labor market restructuring such as unemployment and skill polarization and income disparity has been shaped by the labor market process in the metropolitan cities. This is also closely related to the fact that both industrial restructuring and expanding information technologies in the metropolitan region have reshaped the labor demand structure and finally resulted in structural unemployment due to skill mismatch and spatial mismatch and wage inequality across different occupations. In addition, since wage determination process clearly has a regional dimension, wage determination and its influence on income profile in a certain regional labor market need to be understood by investigating its labor market characteristics including labor supply and demand structure, industrial changes, changing unemployment, etc. This is why labor market policy as a regional policy needs to be redefined and it can be much enhanced by geographical investigation on regional labor market.

• The Journal of Industrial Distribution & Business
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• v.9 no.3
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• pp.19-29
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• 2018

Purpose - This study empirically analyses the changes in unemployment rates to understand push factors of generating wage pressure and how it affects the aggregate demand in Korea and the United States. We use a structural macroeconomic model which is centered on the labor market and simultaneously explains the natural rate of unemployment and deviations. Research design, data and methodology - We attempt to empirically analyse the unemployment rates through two countries to analyse the economic effects of real wages and aggregate demand between 2000 and 2016. We introduce having estimated the whole model that the growth of unemployment into the part caused by each of these factors. Results - The results of this study show that in the long run, there is not only a natural level of employment but also a natural level of real demand are positively related. in the short run, demand can vary from bring about changes in employment by means of price or wage surprises. Conclusions - The pressure of demand in the labor market shows up strongly in both countries. The estimated labor-demand equation are consistent with this framework and generally have well defined real wage and demand effects.

• Economic Analysis
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• v.27 no.1
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• pp.67-90
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• 2021

This study found an interesting fact that the nonlinear relationship structure between volatility and trading volume changed before and after the COVID-19 pandemic according to empirical analysis using Bitcoin (BTC) market data that sensitively reflects investors' trading behavior. That is, their relationship appeared positive (+) in a stable market state before COVID-19 pandemic, as in theory based on the information flow paradigm. In a state under severe market stress due to COVID-19 pandemic, however, their dependence structure changed and even negative (-). This can be seen as a consequence of increased market stress caused by COVID-19 pandemics from a behavioral economics perspective, resulting in structural changes in the asset market and a significant impact on the nonlinear dependence of volatility and trading volume (in particular, their dependence at extreme quantiles). Hence, it should be recognized that in addition to information flows, psychological phenomena such as behavioral biases or herd behavior, which are closely related to market stress, can be a key in changing their dependence structure. For empirical analysis, this study performs a test of Ross (2015) for detecting a structural change, and proposes a Copula Regression Quantiles (CRQ) approach that can identify their nonlinear relationship structure and the asymmetric dependence in their distribution tails without the assumption of i.i.d. random variable. In addition, it was confirmed that when the relationship between their extreme values was analyzed by linear models, incorrect results could be derived due to model specification errors.

• Korea journal of population studies
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• v.20 no.2
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• pp.43-66
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• 1997

This work examines reemployment processes through the use of event history unemployment data in the United States. Two aspects of these processes, the duration of unemployment and changes in the reemployment rate, are modelled and analyzed in terms of individual characteristics and their structural positions in the labor market. The secondary labor market is a competitive market in which unemployment occurs because people quit their jobs to devote more time in search for better jobs. Using search theory, the rate of reemployment has a positive time dependence as the searcher lower her reservation wage with the passage of time. By contrast, the primary market is characterized by long-term employment relations which reduce voluntary turnovers but generate layoffs temporarily. Relying on contract theory, because workers on temporary layoffs wait for recall, reemployment rates have a constant time dependence. Empirical results of unemployment durations indicate that reemployment processes are influenced by individual's positions in dual labor market structures. While the analysis suggests that the amount of search reemployment seems to be positively related to the degree of competitiveness of a market, somewhat weaker results are noted in the search reemployment processes in competitive markets.

• KDI Journal of Economic Policy
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• v.33 no.3
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• pp.57-85
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• 2011

This paper investigates the effects of changes in household structure on service demand. The structure of households in Korea has been quickly changed due to low birth rate and population aging as well as increasing women's participation in the workforce. Their consumption patterns may have been altered by the structural changes. This paper focuses on the additional demand for market services replacing household activities such as household chores and care services. First, using a 3-sector time allocation model, we theoretically analyze the mechanism that marketization of household production can lead to the expansion of service industries. Next, in order to analyze the effects of changes in household structure on consumption demand, we estimate the Engel curves according to the QUAIDS model. For empirical work, the Survey of Household Finances was used. According to the results, structural changes in Korean households, such as an increase in single-person households, a decrease in families with a spouse or children under 6 years old, and an increase in dual-earner households, have caused an increase in medical expenses, education and training costs, and expenses for household services, which are typically substitutes for household production services.

• Journal of Distribution Science
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• v.11 no.10
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• pp.73-79
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• 2013

Purpose - This study examines the impact of oil price volatility on economic activities in Korea. The new millennium has seen a deregulation in the crude oil market, which invited immense capital inflow into Korea. It has also raised oil price levels and volatility. Drawing on the recent theoretical literature that emphasizes the role of volatility, this paper attends to the asymmetric changes in economic growth in response to the oil price movement. This study further examines several key macroeconomic variables, such as interest rate, production, and inflation. We come to the conclusion that oil price volatility can, in some part, explain the structural changes. Research design, data, and methodology - We use two methodological frameworks in this study. First, in regards to the oil price uncertainty, we use an Exponential-GARCH (Exponential Generalized Autoregressive Conditional Heteroskedasticity: EGARCH) model estimate to elucidate the asymmetric effect of oil price shock on the conditional oil price volatility. Second, along with the estimation of the conditional volatility by the EGARCH model, we use the estimates in a VECM (Vector Error Correction Model). The study thus examines the dynamic impacts of oil price volatility on industrial production, price levels, and monetary policy responses. We also approximate the monetary policy function by the yield of monetary stabilization bond. The data collected for the study ranges from 1990: M1 to 2013: M7. In the VECM analysis section, the time span is split into two sub-periods; one from 1990 to 1999, and another from 2000 to 2013, due to the U.S. CFTC (Commodity Futures Trading Commission) deregulation on the crude oil futures that became effective in 2000. This paper intends to probe the relationship between oil price uncertainty and macroeconomic variables since the structural change in the oil market became effective. Results and Conclusions - The dynamic impulse response functions obtained from the VECM show a prolonged dampening effect of oil price volatility shock on the industrial production across all sub-periods. We also find that inflation measured by CPI rises by one standard deviation shock in response to oil price uncertainty, and lasts for the ensuing period. In addition, the impulse response functions allude that South Korea practices an expansionary monetary policy in response to oil price shocks, which stems from oil price uncertainty. Moreover, a comparison of the results of the dynamic impulse response functions from the two sub-periods suggests that the dynamic relationships have strengthened since 2000. Specifically, the results are most drastic in terms of industrial production; the impact of oil price volatility shocks has more than doubled from the year 2000 onwards. These results again indicate that the relationships between crude oil price uncertainty and Korean macroeconomic activities have been strengthened since the year2000, which resulted in a structural change in the crude oil market due to the deregulation of the crude oil futures.

• Journal of the Korea Fashion and Costume Design Association
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• v.3 no.2
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• pp.137-160
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• 2001

A study on the structural change in the U.S. textile industry. The U.S. textile industry has undergone significant changes over the last fifty years, including a steady decline in the relative scale of domestic production, employment reduction, and increased competition from imported products. In order to weather a crisis, the responses of the U.S. textile industry have been made such as investment in technology, specalization in the textile and apparel industries. The textile and apparel industries have taken steps to increase labor productivity through automations to speed management to create and introduce new products and new methods, and have lowered indirect overhead costs. Regarding these response of the U.S. and other situation of world textile and apparel trade market, much of the sense of crisis that pervades korean textile and apparel industries has to do with the problem of adjusting corporate policy.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2007.04a
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• pp.57-61
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• 2007

Changes of construction industry entails needs of new construction technologies. In order to address the needs and new challenges, innovative interdisciplinary research programs are considered to be a good solution. To identify such research programs, technology-push and market needs investigations are conducted. Through analysis of international journals and patent maps, technology fusion-based research program are developed. This paper suggest the strategy for technology fusion-based construction process innovation.

• The Plant Pathology Journal
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• v.31 no.4
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• pp.421-427
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• 2015

Citrus scab disease is one of the destructive diseases that reduce the value of fruit for the fresh market. We analyzed the process of symptom development after infection with scab pathogen $Elsino{\ddot{e}}$ fawcettii in the susceptible satsuma mandarin leaves to observe the structural modification against pathogen. The cuticle and epidermal cells along with 3-5 layers of mesophyll tissue were degraded 1-2 days post inoculation. Surrounding peripheral cells of degraded tissues grew rapidly and then enveloped the necrotic area along with the growing conidia. Cross sections through the lesion revealed hyphal colonization in epidermis and mesophyll tissues. In response to the pathogen colonization, host cell walls were lignified, inner cells were rapidly compartmentalized and a semi-circular boundary was formed that separated the infected region from the non-infected region, and finally prevented the intercellular pathogen spread.