. xtptm _全球价值链参与度   ln_资本密集度  ln_出口密集度  ln_企业规模, rx(ln_新产品产
> 值) thrvar(quality) iters(1000) trim(0.05) grid(100) regime(1)

================ Fundamental information: ===================

Number of Regime independent variables:    3
Number of Regime dependent variables:    1
Number of individuals in panel: 302212
Number of periods in panel:    2

================ Ordinary Fixed effect regression: =========

                 cross():  3900  unable to allocate real <tmp>[604424,604424]
                   ptm():     -  function returned error
                 <istmt>:     -  function returned error
r(3900);