אי-ודאות בפאנלים קצרים

תקציר מקורי באנגליתarXiv:2608.21334v3 Announce Type: replace Abstract: Here is a clear, simple summary in continuous plain text for ArXiv: Short observational pricing panels often contain many data points but very few actual price changes. This paper shows that this sparsity creates a hidden source of error that standard statistical methods miss. When estimating price effects, most of the uncertainty does not come from sample size within a panel, but from the specific history of price movements observed. Standard confidence intervals fail because they only measure variation within the panel, ignoring this broader design-level error. Using simulations, we find that this cross-design variation accounts for most of the estimation error, causing standard methods to significantly understate uncertainty. First, we