Imagine a junior quant on your team has built an ARMA model for the daily returns of a financial asset. They've observed significant volatility clustering in the residuals. Explain why volatility clustering is a problem for standard ARMA models, and propose how models from the GARCH family can address this issue. Furthermore, discuss the key considerations when selecting, estimating, and evaluating GARCH models for financial time series.

一位初级量化分析师对某金融资产的每日收益率构建了一个ARMA模型，但在残差中观察到显著的波动率聚集（volatility clustering）现象。作为资深量化分析师，你需要指导他们。请解释为什么波动率聚集对标准ARMA模型来说是一个问题，并提出如何使用GARCH家族模型来解决这一问题。同时，讨论在为金融时间序列选择、估计和评估GARCH模型时的关键考虑因素。