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991.
The contemporary literature concentrates on ‘make or buy’ decisions in design and production activities, assuming that decisions about the underlying fields of technological knowledge will automatically be the same. Building on previous research on multitechnology firms and products, this paper argues that firms know more about technology than they apply in their own production. We propose two major dimensions according to which firms should adjust their knowledge and production boundaries, namely systemic interdependencies across components and uneven rate of change across components’ underlying knowledge bases. We analyse the implications of this less‐than‐perfect overlap between knowledge and production boundaries for the management of firms’ external relationships.  相似文献   
992.
993.
年度报告是建立公司形象的重要一环,除了向投资者提供公司财务状况的有价值的信息外,还能帮助投资者认识公司的经营情况和未来发展前景.但是这些年度报告是否符合水准呢?来自"五大"的合伙人及一位财务总监提出了他们的观点.  相似文献   
994.
In a transposition cipher the message sequence is subdivided into blocks of equal length and each block is shuffled according to a chosen key. To evaluate the performance of a transposition cipher we take a Shannon-theoretic standpoint and compute relevant equivocations. It is wellknown that transposition ciphers are strongly ideal for memoryless stationary sources (key and cryptogram are independent). We consider also message equivocation and key-appearance equivocation and do not assume that the length of the intercepted cryptogram is a multiple of the block-length. The index of coincidence of the source statistics is shown to be a relevant parameter, at least asymptotically.
Riassunto Il principio della trasposizione è uno dei più antichi in crittografia, ma non è obsoleto: i cifrari a trasposizione vengono adoperati come blocchi costitutivi di alcuni dei più autorevoli cifrari attualmente in uso, come il DES dell'IBM che è stato adottato dal National Bureau of Standards americano. Il messaggio in chiaro che si vuol cifrare viene spezzato in blocchi di ugual lunghezza e ciascun blocco viene «trasposto» (anagrammato) secondo una permutazione fissa e segreta (la chiave del cifrario). In questo lavoro le prestazioni dei cifrari a trasposizione vengono valutate dal punto di vista della teoria di Shannon, calcolando certe «equivocazioni» pertinenti: tali equivocazioni quantificano l'incertezza di una spia che abbia intercettato il crittogramma; dopo l'intercettazione le equivocazioni a priori si trasformano in equivocazioni a posteriori secondo un meccanismo di tipo bayesiano. Se la sorgente dei messaggi è data da un processo stocastico stazionario senza memoria, è ben noto che per quanto concerne la chiave le equivocazioni a priori e a posteriori coincidono: i cifrari a trasposizione sono in questo caso «fortemente ideali».Noi consideriamo anche l'equivocazione sul messaggio e quella sulla «comparsa della chiave» (quest'ultima è significativa nel caso di «attacchi con testo in chiaro»). L'equivocazione sul messaggio si ottiene da quella sulla chiave, che è una costante indipendente dalla lunghezza del crittogramma intercettato, al modo seguente: si somma un contributo periodico che si annulla solo quando tale lunghezza è un multiplo della lunghezza di blocco, e si sottrae una correzione infinitesima (pari all'equivocazione sulla comparsa della chiave) la cui velocità di convergenza è asintoticamente determinata dall' «indice di coincidenza» della distribuzione di probabilità che regola la sorgente dei messaggi.


Questo lavoro è parte del programma di ricerca del GNIM-CNR. È incluso nel programma dell'International Symposium of Information Theory, Brighton (Inghilterra), giugno 1985.  相似文献   
995.
A quantitative examination of the demand for liquid assets arising from consumption smoothing motives reveals that such demand is very low. Consumers faced with income streams calibrated to match income and unemployment data and returns and transactions costs calibrated to match US Treasury Bill data almost exclusively buy and hold illiquid long term assets even though the return premium on long term assets is quite small. This is because, with standard preferences, savings are highly persistent even when risky income is not. In the calibrated model, the first order autocorrelation of savings is an order of magnitude larger than that of income.  相似文献   
996.
Used capital is cheap up front but requires higher maintenance payments later on. We argue that the timing of these investment cash outflows makes used capital attractive to financially constrained firms, since it is cheap when evaluated using their discount factor. In contrast, it may be expensive from the vantage point of an unconstrained agent. We provide an overlapping generations model and determine the price of used capital in equilibrium. Agents with less internal funds are more credit constrained, invest in used capital, and start smaller firms. Empirically, we find that the fraction of investment in used capital is substantially higher for small firms and varies significantly with measures of financial constraints.  相似文献   
997.
We consider a dynamic multifactor model of investment with financing imperfections, adjustment costs and fixed and variable capital. We use the model to derive a test of financing constraints based on a reduced form variable capital equation. Simulation results show that this test correctly identifies financially constrained firms even when the estimation of firms’ investment opportunities is very noisy. In addition, the test is well specified in the presence of both concave and convex adjustment costs of fixed capital. We confirm empirically the validity of this test on a sample of small Italian manufacturing companies.  相似文献   
998.
999.
Following a few general considerations on the recently proposed revision of the Basel Agreement on capital adequacy, this paper focuses on the first pillar of the Basel Committee proposals, the handling of capital requirements for credit risk in the banking book. The Basel Committee envisages an approach alternatively based on external ratings or on internal rating systems for the determination of the minimum capital requirement related to bank loan portfolios. This approach supports a system of capital requirements that is more sensitive to credit risk. On the basis of specific assumptions, these requirements provide a measure of the value at risk (VaR) produced by models used by major international banks. We first address the impact of the standardised and (internal ratings-based) IRB foundation approach using general data on Italian banks loans' portfolios default rates. We then simulate the impact of the proposed new rules on the corporate loan portfolios of Italian banks, using the unique data set of mortality rates recently published by the Bank of Italy. Three main conclusions emerge from the analysis: (i) the standardised approach implicitly penalizes Italian banks in their interbank funding as their rating is generally below AA/Aa, (ii) the average default rate experienced by Italian banks is higher than the one implied in the benchmark risk weight (BRW) proposed by the Basel Committee for the IRB foundation approach, thereby potentially leading to an increase in the regulatory risk weights, and (iii) the risk-weight is based on an average asset correlation that is significantly higher than the one historically recorded within the Italian banks' corporate borrowers. These findings support the need for a significant revision of the basic inputs and assumptions of the Basel proposals. Finally, in relation to the conditions that allow the capital market to effectively discipline banks, we comment on the proposals advanced in relation to the third pillar of the new capital adequacy scheme.  相似文献   
1000.
During the last twenty years an increasing number of proposals to improve bank market discipline through the introduction of a mandatory subordinated debt policy (MSDP) have been presented and critically discussed by academic economists and bank regulators. While theoretical issues are key in this debate, a proper understanding of the market for banks' subordinated notes and debentures (SND) and the main features of securities is also considered relevant for the potential introduction, design and goals setting of such a policy. This paper builds on information concerning issuers, investors, markets, pricing and the technical features of securities to critically discuss these aspects. Data on over 1800 European banks SND issues completed during the 1988–2000:Q1 period together with information on primary and secondary market functioning are presented.  相似文献   
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