Hi,

I have an unbalanced panel dataset (N=2976, T=13), using survey responses.

My dependent variable is the household's ability to save (saving=1 if able to save, 0 otherwise).

hhid is the Household's unique identifier, and the data is yearly.

When I run my model with -xtlogit, re-, there is no issue. But with -xtlogit, fe-, I get an error message.

Please could you help me to understand why this has occurred?

Error message:

Thanks in advance

I have an unbalanced panel dataset (N=2976, T=13), using survey responses.

My dependent variable is the household's ability to save (saving=1 if able to save, 0 otherwise).

hhid is the Household's unique identifier, and the data is yearly.

When I run my model with -xtlogit, re-, there is no issue. But with -xtlogit, fe-, I get an error message.

Please could you help me to understand why this has occurred?

Code:

. xtlogit saving $xlist $controllist i.year, re nolog Random-effects logistic regression Number of obs = 5,241 Group variable: hhid Number of groups = 1,718 Random effects u_i ~ Gaussian Obs per group: min = 1 avg = 3.1 max = 13 Integration method: mvaghermite Integration pts. = 12 Wald chi2(31) = 436.22 Log likelihood = -2756.1286 Prob > chi2 = 0.0000 ------------------------------------------------------------------------------ saving | Coef. Std. Err. z P>|z| [95% Conf. Interval] -------------+---------------------------------------------------------------- precaution | .0287749 .0184366 1.56 0.119 -.0073602 .0649101 purchase | -.0110621 .0180577 -0.61 0.540 -.0464545 .0243303 retirement | .0040648 .0145647 0.28 0.780 -.0244815 .0326111 bequest | .0079644 .0120747 0.66 0.510 -.0157015 .0316303 mediumh | .5228101 .0969268 5.39 0.000 .3328372 .7127831 longh | .3424441 .2626378 1.30 0.192 -.1723164 .8572047 age | -.0588166 .0318057 -1.85 0.064 -.1211546 .0035214 | c.age#c.age | .0003984 .0003009 1.32 0.186 -.0001914 .0009882 | male | .6713149 .1930465 3.48 0.001 .2929507 1.049679 partner | -.2353085 .1627531 -1.45 0.148 -.5542988 .0836818 children | -.4159175 .0725285 -5.73 0.000 -.5580707 -.2737643 house | .6101744 .1524424 4.00 0.000 .3113929 .908956 uni | .5110307 .1732816 2.95 0.003 .1714051 .8506564 employed | .5710195 .2131565 2.68 0.007 .1532405 .9887986 retired | .3504025 .223539 1.57 0.117 -.0877259 .788531 health | .2294954 .0820737 2.80 0.005 .0686339 .390357 incomesc | .0122304 .002279 5.37 0.000 .0077637 .0166971 risk | -.0075499 .0089772 -0.84 0.400 -.0251449 .010045 selfcontrol | .6432303 .0407502 15.78 0.000 .5633615 .7230991 | year | 2005 | -.4750785 .1850209 -2.57 0.010 -.8377129 -.1124441 2006 | -.5867784 .1904732 -3.08 0.002 -.960099 -.2134578 2007 | -.4759589 .1932319 -2.46 0.014 -.8546864 -.0972314 2008 | -.4051887 .1852716 -2.19 0.029 -.7683144 -.0420631 2009 | -.318116 .1857973 -1.71 0.087 -.6822721 .0460401 2010 | -.4950002 .1872916 -2.64 0.008 -.862085 -.1279154 2011 | -.5553593 .233515 -2.38 0.017 -1.01304 -.0976782 2012 | -.3058978 .2329488 -1.31 0.189 -.7624691 .1506735 2013 | -.5059553 .2397291 -2.11 0.035 -.9758156 -.036095 2014 | -.3837295 .227862 -1.68 0.092 -.8303308 .0628719 2015 | -.1927174 .2363871 -0.82 0.415 -.6560277 .2705929 2016 | -.4629798 .2347038 -1.97 0.049 -.9229908 -.0029687 | _cons | -4.710044 1.000298 -4.71 0.000 -6.670592 -2.749497 -------------+---------------------------------------------------------------- /lnsig2u | 1.148462 .1045686 .9435112 1.353413 -------------+---------------------------------------------------------------- sigma_u | 1.775764 .0928446 1.602806 1.967387 rho | .4894052 .0261304 .4384793 .5405521 ------------------------------------------------------------------------------ LR test of rho=0: chibar2(01) = 613.58 Prob >= chibar2 = 0.000

Code:

. xtlogit saving $xlist $controllist i.year, fe nolog note: multiple positive outcomes within groups encountered. note: 1,254 groups (2,734 obs) dropped because of all positive or all negative outcomes. note: male omitted because of no within-group variance. Hessian is not negative semidefinite r(430);

[P] error . . . . . . . . . . . . . . . . . . . . . . . . Return code 430

convergence not achieved;

You have estimated a maximum likelihood model, and Stata's

maximization procedure failed to converge to a solution;

see [R] maximize. Check if the model is identified.

(end of search)

convergence not achieved;

You have estimated a maximum likelihood model, and Stata's

maximization procedure failed to converge to a solution;

see [R] maximize. Check if the model is identified.

(end of search)

## Comment