# Why beta sign is different than correlation sign? [duplicate]

I am trying to interpret the sign of my 5 x-variables against y-variable. The sign of some coefficients in the regression output (command: reg) are different than the signs under correlation matrix (command: correlate). Which one defines the relation sign/direction?

## marked as duplicate by gung♦ regression StackExchange.ready(function() { if (StackExchange.options.isMobile) return; $('.dupe-hammer-message-hover:not(.hover-bound)').each(function() { var$hover = $(this).addClass('hover-bound'),$msg = $hover.siblings('.dupe-hammer-message');$hover.hover( function() { $hover.showInfoMessage('', { messageElement:$msg.clone().show(), transient: false, position: { my: 'bottom left', at: 'top center', offsetTop: -7 }, dismissable: false, relativeToBody: true }); }, function() { StackExchange.helpers.removeMessages(); } ); }); }); Aug 21 '15 at 20:37

• Can you please add the statements as a code block. Would help in understanding the question better. – Dawny33 Aug 21 '15 at 17:11
• In the regression output under the column Coef, it shows -58.17107 for x1. When I ran correlate command to get the correlation matrix, I get 0.8592 correlation value between x1 and y. This difference in signs is confusing. – Asaad Aug 21 '15 at 17:49
• Do a search on Simpson's Paradox. This is a fairly famous statistical concern. – DWin Aug 21 '15 at 19:02
• This page is a good introduction to these issues in the context of logistic regression; the essential issues in terms of independent variables are the same in linear regression. – EdM Aug 21 '15 at 20:14
• I believe you will get the understanding you need in the linked thread. Please read it. If you still have a question afterwards, come back here & edit your Q to state what you've learned & what you still don't understand. Then we can provide the information you need without simply duplicating material elsewhere that already didn't help you. – gung Aug 21 '15 at 20:40