The timing of the response of CO₂ emissions to a carbon tax depends crucially on the timing of the response of energy demand to changes in energy prices. In this paper we investigate the path of changing energy demand from the moment of a change in price until it reaches its new steady state. First, by applying the LeChatelier principle, we show that the response of energy demand in the short run must be smaller than in the long run if firms are only able to adjust their choices of technology in the long run. Secondly, using a putty-clay model with induced technological change, we show that the elasticity of demand approaches its long-run level exponentially at the rate that is determined by the capital depreciation rate and the growth rate of the economy. Thus, according to the model, it takes more than 8 years from the introduction of the carbon tax until half of the long-run effect of induced technological change on energy demand is realised in developed countries. We also illustrate the macroeconomic consequences of the long-run adjustment of energy demand by incorporating the theoretical model into a multi-sector DSGE model of the Polish economy. We find that the adjustment of energy demand reduces the negative impact of CO₂ tax on GDP.

CO ₂的响应时间碳税的排放量主要取决于能源需求对能源价格变化作出反应的时间。在本文中，我们研究了从价格变化到达到新的稳定状态的能源需求变化路径。首先，通过应用 LeChatelier 原理，我们表明，如果企业只能在长期调整其技术选择，那么短期能源需求的响应必须小于长期能源需求的响应。其次，使用具有诱导技术变化的腻子粘土模型，我们表明需求弹性以由资本折旧率和经济增长率决定的速度呈指数级接近其长期水平。因此，根据模型，从征收碳税到发达国家实现技术变革对能源需求的长期影响的一半，需要 8 年多的时间。我们还通过将理论模型纳入波兰经济的多部门 DSGE 模型来说明能源需求长期调整的宏观经济后果。我们发现能源需求的调整降低了 CO 的负面影响₂对 GDP 征税。