Multiple Equilibria and Thresholds Due to Relative Investment Costs
Multiple Equilibria and Thresholds Due to Relative Investment Costs
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相对投资成本导致的多重均衡和阈值
DOI：
10.1023/b:jota.0000043991.06755.af
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发表时间：
2004
期刊：
影响因子：
--
通讯作者：
F. Wirl
中科院分区：
文献类型：
--
作者：
R. Hartl;P. Kort;P. Kort;G. Feichtinger;F. Wirl
研究了企业的动态模型，其中投资成本取决于相对于资本货物存量的投资规模。证明了一般情况下可以存在非唯一的稳态，它可以是稳定的，也可以是不稳定的。在哈密顿函数的凹域内可能出现不稳定的稳态。对于一个特定的规范，一个场景发生在两个稳定的稳定状态和一个不稳定的稳定状态。这两个稳定的稳态是长期平衡；最终到达哪一个取决于初始状态。如果哈密顿函数在不稳定稳态附近是局部凹的，这个稳态就是分离初始条件域的阈值每个稳定稳态吸引的初始条件域。不稳定的稳态是一个节点，投资是资本存量的连续函数。如果不稳定的稳态处于哈密顿函数的非凹域，则该稳态既可以是节点，也可以是焦点。此外，连续性可以（但不需要）保留与凹的情况类似，这一事实在文献中被完全忽视。
A dynamic model of the firm is studied in which investment costs depend on the magnitude of the investment relative to the stock of capital goods. It is shown that in general nonunique steady states can exist which can be stable or unstable. It is possible that unstable steady states occur in the concave domain of the Hamiltonian. For a particular specification, a scenario occurs with two stable steady states and one unstable steady state. The two stable steady states are long run equilibria; which one of them is reached in the long run depends on the initial state. In case the Hamiltonian is locally concave around the unstable steady state, this steady state is the threshold that separates the domain of initial conditions that each of the stable steady states attracts. The unstable steady state is a node and investment is a continuous function of the capital stock. If the unstable steady state lies in the nonconcave domain of the Hamiltonian, this steady state can either be a node or a focus. Furthermore, continuity can (but need not) be retained similarly to the concave case, a fact which has been entirely overlooked in the literature.