NO.PZ2022122601000048
问题如下：
Reed knows that economic growth forecasts are sensitive to theinputs to the Cobb-Douglas production function. He wants to assess the effectof two potential new economic policies on Westria’s future growth path. Thenewly elected government in Westria has proposed the following policies:
Policy 1: Offer incentives to limit theaverage number of children per family.
Policy 2: Increase the maximum allowableannual contribution to tax-free retirement accounts.
Determinewhether each proposed policy will most likely decrease, have no effect on, orincrease the long-run Cobb-Douglas growth projection for Westria. Justify eachresponse with one reason.
解释：
中文解析：
限制每个家庭平均子女数量的激励措施很可能会限制人口增长，因此从长远来看会降低劳动力投入的增长率(ΔL/L)。在保持所有其他因素不变的情况下，降低劳动力投入的增长率将降低长期增长预测。
提高每年向免税退休帐户供款的上限;
很可能会增加储蓄和投资率，从而提高资本存量的增长率(ΔK/K)。在保持其他因素不变的情况下，提高资本存量的增长率将提高长期增长预测。
可以提高全要素生产率(TFP)由于a)技术水平的提高，或b)税收的减少。在保持其他因素不变的情况下，提高全要素生产率的增长率将提高长期增长预测。
如题，哪儿能看出来税收减少从而提升tfp
