• Korean Journal of Logic
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• v.17 no.1
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• pp.109-136
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• 2014

Every (semantic) antirealist accepts one or another form of verification principle. The principle has strong and weak forms, the strong form being highly counterintuitive but the weak one being more plausible. Understandably, antirealists have preferred the weak form of verification principle. Unfortunately, the socalled knowability paradox shows that those two forms are indeed equivalent. To solve this problem, Edgington suggests a yet new form of verification principle. Unfortunately, her new principle has its own difficulty. To overcome this difficulty, Edgington provides a new model of knowledge, according to which every true proposition is somehow associated with a known counterfactual conditional. In this paper, I shall argue that even this new model of knowledge confronts with an insurmountable problem. It is a well-known fact that, in the microscopic levels, some facts manage to occur despite very low physical chances. I will argue that the counterfactuals linked with those facts cannot be known due to the existence of epistemic defeaters. Hence, Edgington's knowledge model does not work in all cases.

• KDI Journal of Economic Policy
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• v.35 no.1
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• pp.103-135
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• 2013

This paper provides consistent understanding between the economic rationale of the 'efficiency' and 'failing firm' defenses and the conditions that the defenses require in the merger assessment process, focusing on two main concepts, 'enhancing competition' and 'counterfactual'. This paper states that the economic rationale of the 'efficiency' defense rests on the effect of enhancing competition rather than on the improvement of efficiency itself. Regarding the 'failing firm' defense, the rationale is stated that competition would not deteriorate even when the merger proceeds compared to the counterfactual where it is prohibited. This understanding reflects not only recent international discussion but also the merger guidelines of advanced competition authorities. It also consistently explains the requirements of the defenses. Finally, this paper includes some comments on the Merger Review Guideline of Korea for its improvement based on various domestic merger cases.

• Language and Information
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• v.15 no.1
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• pp.13-29
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• 2011

Conditional sentences also can be formed by inversion of subject and auxiliary, but it happens only in a limited environment. This paper addresses grammatical constraints in conditional inversion and how they behave differently from the regular conditional clauses based on corpus investigations. Our corpus search reveals many different types of conditional inversion constructions, indicating the difficulties of deriving inverted conditionals from movement operations. In this paper, we provide a construction-based approach to the inverted conditional construction. The paper shows that the most optimal way of describing the general as well as idiosyncratic properties of the inverted conditional constructions is an account in the spirit of construction grammar in which a grammar is a repertory of constructions forming a network connected by links of inheritance.

• KDI Journal of Economic Policy
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• v.39 no.1
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• pp.83-102
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• 2017

Price control can restore efficiency in some cases, but an uncarefully designed policy fails to restore efficiency, yields side effects, or even exacerbates efficiency losses. This paper shows that the copyright royalty rule, which takes the greater of ad valorem royalties and perunit royalties, tends to fix the prices of final goods at a specific level. Such a rule weakens competition as it prevents prices from decreasing even when market conditions change, having negative effects on social welfare as well as consumer surplus. Counterfactual analyses using estimation results in the Korean online music service industry show that firms could have profitably reduced prices if the ad valorem rule had been applied instead, although they did not have an incentive to do so under the original combination rule.

• Proceedings of the Korea Information Processing Society Conference
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• 2021.11a
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• pp.830-833
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• 2021

인공지능 기술이 사회 전반에 적용되면서 인공지능에 대한 인간의 이해도 역시 중요해지고 있다. 이러한 필요성을 기반으로 설명 가능한 인공지능(XAI) 분야 연구가 현재 활발히 진행되고 있다. 이 중 입력의 변화를 통하여 반사실적 대안을 제시하는 반사실적 예제 기반의 설명은 피쳐수가 많아지는 이미지 데이터에서 연산량이 크게 증가하는 단점이 있다. 본 연구에서는 이러한 단점을 해결하고자 이미지의 추상화된 피쳐 영역에서 프로토타입 피쳐를 이용한 반사실적 예제를 생성하는 기법을 제안한다. 나아가 이러한 이미지 형식의 반사실적 예제를 활용할 분야를 제시하고자 한다.

• Korean Journal of Logic
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• v.15 no.3
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• pp.347-375
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• 2012

In my article published in 2008, I offered an inferentialist account of indicative conditionals. In her recent paper, Professor Seawha Kim raises three objections. First, I misunderstand Sellars-Brandom in that I take only concept-constitutive inferences as materially valid inferences. Second, Sellars and Brandom talk about the common features of all kinds of conditionals including counterfactual conditionals, but I construe their view as the analysis of the indicative conditionals only. Third, either my analysis is incompatible with Sellars-Brandom inferentialism or my analysis is too general. In this paper I argue that Seawha Kim's objections are all based on insufficient understandings of Sellars's and Brandom's views. First, it is Sellars's view that materially valid inferences are restricted within concept-constitutive inferences. Second, neither Sellars nor Brandom proposes a specific theory about the indicative conditional. Instead, they argue for the expressive role of the conditional. What I accept from their views is this expressive role of the conditional. The detailed proposals about the indicative conditional in my aforementioned article are my own. Third, the differences among conditionals have no direct bearing on Sellars-Brandom inferentialism. In addition, the meaning and role of the conditional expression 'if-then' do not require more than what I have argued for it.

• Korean Journal of Logic
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• v.5 no.2
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• pp.115-131
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• 2002

The problem of disjunctive causal factors is generalized as follows. Suppose that there are no factors of the kind considered so far that need to be held fixed in background contexts. Nevertheless, it is still possible that within the background contexts, each disjunct of a disjunctive causal factor X v W confers a different probability on an effect factor in Question. So a problem arises of how we identify a single causally significant probability of the effect factor in the presence of the disjunctive causal factor, assuming that each disjunct of the disjunctive causal factor confers a different probability on the effect factor. In this paper, I first introduce an experiment in which disjunctive causal factors seem to pose a problem for the theory of probabilistic causation. Second, I show how Eells' solution to the problem of disjunctive causal factors meets the problem that arises in the experiment. Third, I examine Hitchcock's arguments against Eells' solution, arguing that Hitchcock misconstrues Eells' solution, and disregards the feature of the theory of probabilistic causation such that a factor is a causal factor for another factor relative to a population P of a population type Q.

• Korean Journal of Logic
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• v.15 no.2
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• pp.251-272
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• 2012

Recently Professor Lee has suggested the analysis of the indicative conditional based on Sellars-Brandom's inferentialism. In this paper, I raise three questions. First, Professor Lee seems to misunderstand Sellars-Brandom in that he considers only the analytically valid arguments as materially valid inferences. Second, Professor Lee seems to misunderstand Sellars-Brandom in that whereas Sellars-Brandom talks about the common features of all kinds of conditionals including counterfactual conditionals, Professor Lee takes it as the analysis of the indicative conditional only. Third, either Professor Lee's analysis is incompatible with Sellars-Brandom inferentialism or his analysis is too general.

• Journal of Preventive Medicine and Public Health
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• v.40 no.6
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• pp.495-504
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• 2007

Objectives : This study attempts to show how studies using non-experimental data can strengthen causal inferences by applying propensity score and instrumental variable methods based on the counterfactual framework. For illustrative purposes, we examine the effect of having private health insurance on the probability of experiencing at least one hospital admission in the previous year. Methods : Using data from the 4th wave of the Korea Labor and Income Panel Study, we compared the results obtained using propensity score and instrumental variable methods with those from conventional logistic and linear regression models, respectively. Results : While conventional multiple regression analyses fail to identify the effect, the results estimated using propensity score and instrumental variable methods suggest that having private health insurance has positive and statistically significant effects on hospital admission. Conclusions : This study demonstrates that propensity score and instrumental variable methods provide potentially useful alternatives to conventional regression approaches in making causal inferences using non-experimental data.

• East Asian Economic Review
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• v.23 no.1
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• pp.27-53
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• 2019

I employ search-and-matching to a multi-country and multi-sector Ricardian model with input-output linkages, trade in intermediate goods, and sectoral heterogeneity, in order to quantify the welfare effects from tariff changes. The paper shows that labor market frictions can be a source of comparative advantage in the sense that better labor market conditions contribute to lower cost in production. Labor market frictions play a critical role in determining the probability of exporting goods to trading partners, and interact with bilateral trade share, price, expenditures, etc. Unemployment and changes in unemployment rates due to tariff reductions contribute welfare changes across countries, implying that welfare effects based on quantitative trade models with full-employment are likely to be biased. I confirm the biased welfare effects by revisiting Caliendo and Parro (2015), who conduct an analysis of the welfare effects from the NAFTA from 1993 to 2005. I show that the welfare gap between theirs and mine has a positive correlation with changes in observed unemployment rates across countries. With the constructed model, I further conduct counterfactual exercises by asking what would happen if China's tariffs remain unchanged from 2006 to 2015. It turns out that there are mild welfare effects to trading partners in the world trading system.