\begin{tabular}{l cc c cc c cc}
\toprule
 & \multicolumn{2}{c}{Random 80/20} & & \multicolumn{2}{c}{Parcel-grouped} & & \multicolumn{2}{c}{Building-grouped} \\
\cmidrule{2-3}\cmidrule{5-6}\cmidrule{8-9}
Model & MdAPE & $R^2_{\ln}$ & & MdAPE & $R^2_{\ln}$ & & MdAPE & $R^2_{\ln}$ \\
\midrule
\multicolumn{9}{l}{\itshape A. Functional form}\\
\quad A1 Linear & 18.2 & 0.477 &  & 18.4 & 0.469 &  & 18.4 & 0.473 \\
\quad A2 Semi-log & 19.0 & 0.546 &  & 19.4 & 0.528 &  & 19.5 & 0.530 \\
\quad A3 Log-log & 18.0 & 0.580 &  & 18.0 & 0.572 &  & 18.1 & 0.573 \\
\quad A4 Box--Cox & 18.6 & 0.548 &  & 18.2 & 0.534 &  & 18.3 & 0.535 \\
\quad A5 Quadratics & 19.2 & 0.546 &  & 19.2 & 0.539 &  & 19.0 & 0.552 \\
\quad A6 Splines & 17.6 & 0.590 &  & 17.6 & 0.581 &  & 17.8 & 0.582 \\
\multicolumn{9}{l}{\itshape B. Time effects}\\
\quad B1 No time FE & 22.0 & 0.486 &  & 21.6 & 0.489 &  & 22.0 & 0.482 \\
\quad B2 Year FE & 19.1 & 0.545 &  & 19.0 & 0.545 &  & 19.2 & 0.539 \\
\quad B3 Quarter FE & 19.2 & 0.546 &  & 19.2 & 0.539 &  & 19.0 & 0.552 \\
\quad B4 Month FE & 19.3 & 0.543 &  & 19.3 & 0.537 &  & 19.4 & 0.538 \\
\multicolumn{9}{l}{\itshape C. Spatial controls}\\
\quad C1 No spatial FE & 28.8 & 0.307 &  & 28.9 & 0.301 &  & 28.7 & 0.306 \\
\quad C2 Municipality FE & 19.2 & 0.546 &  & 19.2 & 0.539 &  & 19.0 & 0.552 \\
\quad C3 Grid 5.5 km & 18.7 & 0.557 &  & 18.7 & 0.550 &  & 18.8 & 0.551 \\
\quad C4 Grid 1.1 km & 21.0 & 0.496 &  & 21.1 & 0.491 &  & 20.2 & 0.510 \\
\multicolumn{9}{l}{\itshape D. Estimation method}\\
\quad D1 OLS & 19.3 & 0.543 &  & 19.3 & 0.537 &  & 19.4 & 0.538 \\
\quad D2 Ridge & 17.7 & 0.587 &  & 17.7 & 0.580 &  & 17.9 & 0.580 \\
\quad D3 Random forest & 14.6 & 0.631 &  & 14.6 & 0.620 &  & 14.9 & 0.621 \\
\quad D4 Boosting & 14.4 & 0.642 &  & 14.5 & 0.632 &  & 14.6 & 0.634 \\
\quad D5 Boosting, no coord. & 23.2 & 0.426 &  & 23.4 & 0.417 &  & 23.3 & 0.420 \\
\quad D6 $k$-NN comparables & 21.2 & 0.434 &  & 21.3 & 0.442 &  & 22.3 & 0.425 \\
\midrule
Test sales & 102,929 & & & 102,843 & & & 102,949 & \\
\bottomrule
\end{tabular}