<TABLE> <S> <C>

<PAGE>
<ARTICLE> 5
<LEGEND>
THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM
BARRA, INC CONSOLIDATED FINANCIAL STATEMENTS AS OF AND FOR THE THREE AND
NINE MONTHS ENDED DECEMBER 31, 1997 AND IS QUALIFIED IN ITS ENTIRETY BY
REFERENCE TO SUCH FINANCIAL STATEMENTS.
</LEGEND>
       
<S>                             <C>                     <C>
<PERIOD-TYPE>                   9-MOS                   3-MOS
<FISCAL-YEAR-END>                          MAR-31-1998             MAR-31-1998
<PERIOD-START>                             APR-01-1997             OCT-01-1997
<PERIOD-END>                               DEC-31-1997             DEC-31-1997
<CASH>                                      14,713,493                       0
<SECURITIES>                                14,007,404                       0
<RECEIVABLES>                               30,547,800                       0
<ALLOWANCES>                                   138,022                       0
<INVENTORY>                                          0                       0
<CURRENT-ASSETS>                            68,113,847                       0
<PP&E>                                      27,867,289                       0
<DEPRECIATION>                              13,660,609                       0
<TOTAL-ASSETS>                             115,461,147                       0
<CURRENT-LIABILITIES>                       46,914,356                       0
<BONDS>                                              0                       0
<PREFERRED-MANDATORY>                                0                       0
<PREFERRED>                                          0                       0
<COMMON>                                    23,656,369                       0
<OTHER-SE>                                  39,036,101                       0
<TOTAL-LIABILITY-AND-EQUITY>                61,913,162                       0
<SALES>                                    101,100,519              42,759,864
<TOTAL-REVENUES>                           101,100,519              42,759,864
<CGS>                                        5,224,013               2,010,924
<TOTAL-COSTS>                               82,987,756              28,237,951
<OTHER-EXPENSES>                                     0                       0
<LOSS-PROVISION>                                     0                       0
<INTEREST-EXPENSE>                                   0                       0
<INCOME-PRETAX>                             12,558,978               9,703,575
<INCOME-TAX>                                 9,489,934               4,045,975
<INCOME-CONTINUING>                         12,558,978               9,703,575
<DISCONTINUED>                                       0                       0
<EXTRAORDINARY>                                      0                       0
<CHANGES>                                            0                       0
<NET-INCOME>                                 3,069,044               5,657,600
<EPS-PRIMARY>                                      .23                     .42
<EPS-DILUTED>                                      .22                     .39
<FN>
<F1> INCLUDED IN TOTAL COSTS AND EXPENSES ARE ONE-TIME ACQUISITION CHARGES OF
$9,914,000 FOR THE NINE MONTH PERIOD ENDED DECEMBER 31, 1997 REPRESENTING
PURCHASED IN-PROCESS RESEARCH AND DEVELOPMENT IN CONNECTION WITH THE
ACQUISITIONS OF GAT AND INNOSEARCH ON JUNE 24, 1997.  AS REQUIRED BY GENERALLY
ACCEPTED ACCOUNTING PRINCIPLES, THE PORTION OF THE PURCHASE PRICE ALLOCATED TO
PURCHASED TECHNOLOGY WAS IMMEDIATELY EXPENSED.
</FN>
        

</TABLE>